BioLargo (BLGO) 10-Q14 May 242024 Q1 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
Document And Entity Information - shares	Mar. 31, 2024	May 13, 2024
Document Information [Line Items]
Entity Central Index Key	0000880242
Entity Registrant Name	BIOLARGO, INC.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2024
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	000-19709
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	65-0159115
Entity Address, Address Line One	14921 Chestnut St.
Entity Address, City or Town	Westminster
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92683
City Area Code	888
Local Phone Number	400-2863
Title of 12(b) Security	Common stock
Trading Symbol	BLGO
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		296,839,523

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 4,336,000	$ 3,539,000
Accounts receivable, net of allowance	2,473,000	2,612,000
Inventories, net of allowance	251,000	153,000
Prepaid expenses and other current assets	116,000	58,000
Total current assets	7,176,000	6,362,000
Equipment and leasehold improvements, net of depreciation	1,489,000	662,000
Other non-current assets	70,000	70,000
Investment in South Korean joint venture	18,000	19,000
Right of use, operating lease, net of amortization	1,068,000	1,092,000
Total assets	9,821,000	8,205,000
Current liabilities:
Total	1,740,000	1,488,000
Debt obligation	66,000	66,000
Contract liabilities	261,000	303,000
Lease liability	1,090,000	1,109,000
Deposits	226,000	117,000
Total current liabilities	3,404,000	2,710,000
Long-term liabilities:
Long-Term Debt, Excluding Current Maturities	284,000	289,000
Lease liability, net of current	985,000	1,004,000
Total long-term liabilities	1,269,000	1,293,000
Total liabilities	4,673,000	4,003,000
STOCKHOLDERS’ EQUITY:
Preferred Series A, $0.00067 Par Value, 50,000,000 Shares Authorized, no Shares Issued and Outstanding, at March 31, 2024 and December 31, 2023	0	0
Common stock, $0.00067 Par Value, 550,000,000 Shares Authorized, 295,801,370 and 292,945,747 Shares Issued, at March 31, 2024 and December 31, 2023	198,000	196,000
Additional paid-in capital	155,606,000	154,023,000
Accumulated deficit	(147,508,000)	(147,098,000)
Accumulated other comprehensive loss	(181,000)	(277,000)
Total BioLargo Inc. and subsidiaries stockholders’ equity	8,115,000	6,844,000
Non-controlling interest (Note 8, 9, 10)	(2,967,000)	(2,642,000)
Total stockholders’ equity	5,148,000	4,202,000
Total liabilities and stockholders’ equity	9,821,000	8,205,000
Entities, Excluding Partially Owned Subsidiary [Member]
Current liabilities:
Total	1,740,000	1,488,000
Partially Owned Subsidiary [Member]
Current liabilities:
Total	772,000	397,000
Lease liability	105,000	105,000
Clyra Medical Debt Obligations [Member]
Current liabilities:
Long term debt	$ 234,000	$ 234,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Convertible Preferred Stock, Par Value (in dollars per share)	$ 0.00067	$ 0.00067
Convertible Preferred Stock, Shares Authorized (in shares)	50,000,000	50,000,000
Convertible Preferred Stock, Shares Issued (in shares)	0	0
Convertible Preferred Stock, Shares Outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.00067	$ 0.00067
Common stock, shares authorized (in shares)	550,000,000	550,000,000
Common stock, shares issued (in shares)	295,801,370	292,945,747

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue from Contract with Customer, Including Assessed Tax	$ 4,760,000	$ 3,742,000
Cost of revenue
Cost of Goods and Services Sold	(2,514,000)	(1,932,000)
Gross profit	2,246,000	1,810,000
Selling, general and administrative expenses	2,225,000	1,722,000
Research and development	784,000	565,000
Total operating expenses	3,009,000	2,287,000
Operating loss	(763,000)	(477,000)
Other (expense) income:
Interest expense	(12,000)	(48,000)
Grant income	0	31,000
Total other expense:	(12,000)	(17,000)
Net loss	(775,000)	(494,000)
Net loss attributable to noncontrolling interest	(365,000)	(247,000)
Net loss attributable to common shareholders	$ (410,000)	$ (247,000)
Net loss per share attributable to common shareholders:
Loss per share attributable to shareholders – basic and diluted (in dollars per share)	$ (0.001)	$ (0.001)
Weighted average number of common shares outstanding: (in shares)	294,308,798	280,711,278
Comprehensive loss:
Net loss	$ (775,000)	$ (494,000)
Foreign currency translation	96,000	(6,000)
Comprehensive loss	(679,000)	(500,000)
Comprehensive loss attributable to noncontrolling interest	(365,000)	(247,000)
Comprehensive loss attributable to common stockholders	(314,000)	(253,000)
Product [Member]
Revenue from Contract with Customer, Including Assessed Tax	4,575,000	3,548,000
Cost of revenue
Cost of Goods and Services Sold	(2,440,000)	(1,797,000)
Service [Member]
Revenue from Contract with Customer, Including Assessed Tax	185,000	194,000
Cost of revenue
Cost of Goods and Services Sold	$ (74,000)	$ (135,000)

Condensed Consolidated Statemen

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Clyra Medical [Member] Common Stock [Member]	Clyra Medical [Member] Additional Paid-in Capital [Member]	Clyra Medical [Member] Retained Earnings [Member]	Clyra Medical [Member] AOCI Attributable to Parent [Member]	Clyra Medical [Member] Noncontrolling Interest [Member]	Clyra Medical [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Common Stock [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Additional Paid-in Capital [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Retained Earnings [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] AOCI Attributable to Parent [Member]	BioLargo Energy Technologies, Inc (BETI) [Member] Noncontrolling Interest [Member]	BioLargo Energy Technologies, Inc (BETI) [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2022													278,462,706
Balance at Dec. 31, 2022													$ 186,000	$ 148,435,000	$ (143,594,000)	$ (149,000)	$ (2,867,000)	$ 2,011,000
Sale of stock for cash, net of offering costs of $39 (unaudited) (in shares)													4,201,402
Sale of stock for cash, net of offering costs of $39 (unaudited)													$ 3,000	797,000	0	0	0	800,000
Stock for service (in shares)													930,490
Issuance of common stock for services (unaudited)													$ 1,000	206,000	0	0	0	207,000
Stock option compensation expense (unaudited)													0	195,000	0	0	0	195,000
Clyra Medical stock options issued for services (unaudited)													0	61,000	0	0	0	61,000
Clyra Medical stock issued for services (unaudited)							$ 0	$ 0	$ 0	$ 0	$ 550,000	$ 550,000	0	0	0	0	225,000	225,000
Clyra Medical Preferred Series A dividend (unaudited)													0	0	0	0	(27,000)	(27,000)
Noncontrolling interest allocation (unaudited)													0	467,000	0	0	(467,000)	0
Net loss													0	0	(247,000)	0	(247,000)	(494,000)
Foreign currency translation (unaudited)													$ 0	0	0	(6,000)	0	(6,000)
Balance (in shares) at Mar. 31, 2023													284,122,581
Balance at Mar. 31, 2023													$ 190,000	150,191,000	(143,841,000)	(155,000)	(2,833,000)	3,552,000
Issuance of common stock in exchange for Clyra shares (in shares)													527,983
Warrant issued for interest													$ 0	30,000	0	0	0	30,000
Balance (in shares) at Dec. 31, 2023													292,945,747
Balance at Dec. 31, 2023													$ 196,000	154,023,000	(147,098,000)	(277,000)	(2,642,000)	4,202,000
Sale of stock for cash, net of offering costs of $39 (unaudited) (in shares)													2,160,348
Sale of stock for cash, net of offering costs of $39 (unaudited)													$ 1,000	487,000	0	0	0	488,000
Stock for service (in shares)													288,997
Issuance of common stock for services (unaudited)													$ 1,000	82,000	0	0	0	83,000
Warrant exercise (unaudited)													0	75,000	0	0	0	75,000
Stock option compensation expense (unaudited)													0	429,000	0	0	0	429,000
Clyra Medical stock options issued for services (unaudited)													0	59,000	0	0	0	59,000
Clyra Medical stock issued for services (unaudited)													0	52,000	0	0	0	52,000
Clyra Medical common unit offering (unaudited)	$ 0	$ 0	$ 0	$ 0	$ 475,000	$ 475,000	$ 0	$ 0	$ 0	$ 0	$ 50,000	$ 50,000
Clyra Medical Preferred Series A dividend (unaudited)													0	0	0	0	(86,000)	(86,000)
Noncontrolling interest allocation (unaudited)													0	399,000	0	0	(399,000)	0
Net loss													0	0	(410,000)	0	(365,000)	(775,000)
Foreign currency translation (unaudited)													$ 0	0	0	96,000	0	96,000
Balance (in shares) at Mar. 31, 2024													295,801,370
Balance at Mar. 31, 2024													$ 198,000	$ 155,606,000	$ (147,508,000)	$ (181,000)	$ (2,967,000)	$ 5,148,000
Warrant exercise (unaudited) (in shares)													406,278

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Offering Cost	$ 39

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net loss	$ (775,000)	$ (494,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock option compensation expense	488,000	256,000
Common stock issued for services	135,000	207,000
Amortization of right-of-use operating lease assets	24,000	0
Interest expense related to amortization of the discount on note payable	0	3,000
Fair value of warrant issued for interest	0	30,000
Loss on investment in South Korean joint venture	1,000	6,000
Depreciation expense	36,000	22,000
Changes in assets and liabilities:
Accounts receivable	139,000	(316,000)
Inventories	(98,000)	(17,000)
Prepaid expenses and other assets	(58,000)	25,000
Deposits	109,000	(71,000)
Contract liabilities	(42,000)	4,000
Lease liability, net	(19,000)	4,000
Net cash provided by (used in) operating activities	481,000	(43,000)
Cash flows from investing activities
Equipment purchases	(863,000)	(48,000)
Net cash used in investing activities	(863,000)	(48,000)
Cash flows from financing activities
Proceeds from sale of common stock, net of commissions	488,000	800,000
Proceeds from warrant exercise	75,000	0
Repayment of debt obligations	(5,000)	(50,000)
Repayment by Clyra debt obligations	0	(15,000)
Proceeds from sale of Clyra Medical preferred stock	0	225,000
Net cash provided by financing activities	1,083,000	1,510,000
Net effect of foreign currency translation	96,000	(6,000)
Net change in cash	797,000	1,413,000
Cash and cash equivalents at beginning of period	3,539,000	1,851,000
Cash and cash equivalents at end of period	4,336,000	3,264,000
Supplemental disclosures of cash flow information
Interest	12,000	15,000
Income taxes	0	5,000
Short-term lease payments not included in lease liability	12,000	13,000
Non-cash investing and financing activities
Equipment added using capital lease	0	80,000
Allocation of noncontrolling interest	399,000	467,000
Preferred Series A Dividend	86,000	0
Conversion of Clyra Common Stock to BioLargo Common Stock [Member]
Non-cash investing and financing activities
Conversion of Clyra common stock to BioLargo common stock	0	100,000
BETI Common Stock [Member]
Cash flows from financing activities
Proceeds from sale of common stock, net of commissions	50,000	550,000
Clyra Medical Common Stock [Member]
Cash flows from financing activities
Proceeds from sale of common stock, net of commissions	475,000	0
Entities, Excluding Partially Owned Subsidiary [Member]
Changes in assets and liabilities:
Accounts payable and accrued expenses	252,000	284,000
Partially Owned Subsidiary [Member]
Changes in assets and liabilities:
Accounts payable and accrued expenses	$ 289,000	$ 14,000

Note 1 - Business and Organizat

Note 1 - Business and Organization	3 Months Ended
Note 1 - Business and Organization	Mar. 31, 2024
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Note 1. Description of Business BioLargo, Inc. (“BioLargo”, or the “Company”) invents, develops, and commercializes innovative platform technologies to solve challenging environmental problems like PFAS contamination (per- and polyfluoroalkyl substances), advanced water and wastewater treatment, industrial odor control, air quality control, infection control, and myriad environmental remediation challenges. Our business strategy is straightforward: we invent or acquire technologies that we believe have the potential to be disruptive in large commercial markets; we develop and validate these technologies to advance and promote their commercial success as we leverage our considerable scientific, engineering, and entrepreneurial talent; we then monetize these technical assets through a variety of business structures that may Organization We are a Delaware corporation formed in 1991. five 2006; 2009; 2022; 2014; 2016. three 2012 2023; 2017; 2019. Liquidity / Going Concern For the three March 31, 2024 March 31, 2024 While we were able to generate $481,000 net cash from operating activities during the three March 31, 2024 not third three March 31, 2024 The foregoing factors raise substantial doubt about our ability to continue as a going concern, unless we are able to (i) continue to increase revenues, generate cash from operations, or generate cash from financing activities, (ii) convert assets such as our $2,473,000 in accounts receivable into cash; or, (iii) if necessary, reduce ongoing cash obligations by curtailing portions of our operations.

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	3 Months Ended
Note 2 - Summary of Significant Accounting Policies	Mar. 31, 2024
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries, and partially owned subsidiaries BETI, BLEST and Clyra Medical. All intercompany accounts and transactions have been eliminated. The accounting and financial reporting policies of the Company conform, in all material respects, to accounting principles generally accepted in the United States of America (“GAAP”) and to general practices within the industry. The condensed consolidated financial statements in the Quarterly Report on Form 10 not 10 not December 31, 2023, 10 April 1, 2024. three March 31, 2024 not Foreign Currency The Company has designated the functional currency of BioLargo Canada, Inc., our Canadian subsidiary, to be the Canadian dollar. Therefore, translation gains and losses resulting from differences in exchange rates are recorded in accumulated other comprehensive loss. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three one $250,000 not As of March 31, 2024 December 31, 2023 March 31, 2024 December 31, 2023 BioLargo, Inc. and subsidiaries $ 4,242 $ 3,142 Clyra Medical Technologies, Inc. 94 397 Total $ 4,336 $ 3,539 Accounts Receivable In June 2016, 2016 13, January 1, 2023 Accounts receivable are customer obligations that are unconditional. Accounts receivable are presented net of an allowance for doubtful accounts for expected credit losses, which represents an estimate of amounts that may not no not March 31, 2024 December 31, 2023 Credit Concentration We have a limited number of customers that account for significant portions of our revenue. During the three March 31, 2024 2023 10% Three Months ended March 31, 2024 2023 Customer A 88 % 86 % At March 31, 2024 December 31, 2023 one March 31, 2024 December 31, 2023 Customer A 79 % 68 % Inventory Inventories are stated at the lower of cost or net realizable value using the average cost method. The allowance for obsolete inventory as of March 31, 2024 December 31, 2023 March 31, 2024 December 31, 2023 Raw material $ 85 $ 79 Finished goods 166 74 Total $ 251 $ 153 Other Non-Current Assets Other non-current assets consisted of (i) security deposits related to our business offices, (ii) three October 22, 2021, March 31, 2024 December 31, 2023 Patents $ 34 $ 34 Security deposits 36 36 Total $ 70 $ 70 Equity Method of Accounting On March 20, 2020, We account for our investment in the joint venture under the equity method of accounting. We have determined that while we have significant influence over the joint venture through our technology license and our position on the Board of Directors, we do not three March 31, 2024 2023 Impairment Long-lived and definite lived intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not no three March 31, 2024 2023 Loss Per Share We report basic and diluted loss per share (“LPS”) for common and common share equivalents. Basic LPS is computed by dividing reported losses by the weighted average shares outstanding. Diluted LPS is computed by adding to the weighted average shares the dilutive effect if stock options and warrants were exercised into common stock. For the three March 31, 2024 2023 Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and revenues and expenses during the period reported. Actual results could differ from those estimates. Estimates are used when accounting for stock-based transactions, debt transactions, derivative liabilities, allowance for doubtful accounts, asset depreciation and amortization, impairment expense, among others. The methods, estimates and judgments we use in applying these most critical accounting policies have a significant impact on the results of our condensed consolidated financial statements. Share-Based Compensation Expense We recognize compensation expense for stock option awards on a straight-line basis over the applicable service period of the award, which is the vesting period. Fair value is determined on the grant date. Share-based compensation expense is based on the grant date fair value estimated using the Black-Scholes Option Pricing Model. For stock and stock options issued to consultants and other non-employees for services, the Company measures and records an expense as of the earlier of the date at which either: a commitment for performance by the non-employee has been reached or the non-employee’s performance is complete. The equity instruments are measured at the current fair value, and for stock options, the instruments are measured at fair value using the Black Scholes option model. The following methodology and assumptions were used to calculate share-based compensation for the three March 31, 2024 2023 2024 2023 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate — % 4.16 % 3.48 % 3.48 % Expected volatility — % 99 % 114 % 114 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years — 10 10 10 Expected price volatility is the measure by which our stock price is expected to fluctuate during the expected term of an option. The expected volatility is derived from the historical daily change in the market price of our common stock, as we believe that historical volatility is the best indicator of future volatility. The risk-free interest rate used in the Black-Scholes calculation is based on the prevailing U.S. Treasury yield as determined by the U.S. Federal Reserve. We have never paid any cash dividends on our common stock and do not Warrants Warrants issued with our convertible and non-convertible debt instruments are accounted for under the fair value and relative fair value method. The warrant is first not. not not Non-Cash Transactions We determine the value assigned to each intangible we acquire, and/or services or products received for non-cash consideration of our common stock based on the market price of our common stock issued as consideration, at the date of the agreement of each transaction or when the service is rendered or product is received. Revenue Recognition We account for revenue in accordance with ASC 606, Step 1: Step 2: Step 3: Step 4: Step 5: The Company’s products are sold through a contract with the customer and a written purchase order, in which the details of the contract are defined including the transaction price and method of shipment. The only performance obligation is to create and ship the product, and each product has separate pricing. Revenue is recognized at a point in time when the goods are shipped if the agreement is FOB manufacturer, and when goods are delivered if FOB destination. Revenue is recognized with a reduction for sales discounts, as appropriate and negotiated in the customer’s purchase order. Service contracts are performed through a written contract, which specifies the performance obligations and the rate at which the services will be billed, typically by time and materials. Each service is separately negotiated and priced. Revenue is recognized as services are performed and completed, or, for services related to product installations, at the completion of the installation. A few contracts have called for milestone or fixed cost payments, where we invoice an agreed-to amount per month for the life of the contract. In these instances, completed work, billed hourly, is recognized as revenue. If the billing amount is greater or lesser than the completed work, a receivable or payable is created. These accounts are adjusted upon additional billings as the work is completed. To date, there have been no The Company has outstanding contract liability obligations of $261,000 and $303,000 as of March 31, 2024, December 31, 2023, three March 31, 2024. March 31, 2024 December 31, 2023, March 31, 2024 December 31, 2023, not three March 31, 2024. As we generate revenues from royalties or license fees from our intellectual property, a licensee will pay a license fee in one third Government Grants We have been awarded multiple research grants from the private and public Canadian research programs. The income we receive directly from grants is recorded as other income. We have been awarded over 80 first 2015. third third six eighteen not The grants typically provide for (i) recurring monthly amounts, (ii) reimbursement of costs for research talent for which we invoice to request payment, and (iii) ancillary cost reimbursement for research talent travel related costs. All awarded grants have specific requirements on how the money is spent, typically to employ researchers. None may Not no Income Taxes The asset and liability approach is used to recognize deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of asset and liabilities. Deferred tax assets and liabilities are determined based on the differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The effect on deferred tax asset and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. We account for uncertainties in income tax law under a comprehensive model for the financial statement recognition, measurement, presentation, and disclosure of uncertain tax positions taken or expected to be taken in income tax returns as prescribed by GAAP. Under GAAP, the tax effects of a position are recognized only if it is “more-likely-than- not” not not” no March 31, 2024 December 31, 2023 The Company assessed its earnings history, trends and estimates of future earnings and determined that the deferred tax asset could not March 31, 2024 December 31, 2023 100% The Company recognizes interest and penalties on income taxes as a component of income tax expense, should such an expense be realized. Fair Value of Financial Instruments Management believes the carrying amounts of the Company’s financial instruments as of March 31, 2024 December 31, 2023 Leases At inception of a lease contract, we assess whether the contract is, or contains, a lease. Our assessment is based on: ( 1 2 3 not no not not 12 not March 31, 2024 December 31, 2023 March 31, 2024 December 31, 2023 Property and Equipment Property and equipment includes machinery and leasehold improvements and is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which range from 3 - 10 years or the remaining lease term. Newly built leaseholds, additions, renewals, and betterments that significantly extend the life of the asset are capitalized. Expenditures for repairs and maintenance are charged to expense as incurred. For assets sold or otherwise disposed of, the cost and related accumulated depreciation and amortization are removed from the accounts, and any related gain or loss is reflected in income for the period. Noncontrolling Interest A noncontrolling interest is defined as the portion of the equity in an entity not not 810 10 20, three December 31, 2023 2022. December 31, 2023, 2022, December 31, 2023. 2023.

Note 3 - Sale of Stock for Cash

Note 3 - Sale of Stock for Cash	3 Months Ended
Note 3 - Sale of Stock for Cash	Mar. 31, 2024
Notes to Financial Statements
Stock Purchase Agreement [Text Block]	Note 3. Lincoln Park Financing On December 13, 2022, “2022 three may three 12 no first 2022 1 December 23, 2022. January 19, 2023. During the three March 31, 2024 2023 Unit Offerings During the three March 31, 2024 five three March 31, 2023, eleven six five 6,

Note 4 - Debt Obligations

Note 4 - Debt Obligations	3 Months Ended
Note 4 - Debt Obligations	Mar. 31, 2024
Notes to Financial Statements
Debt Disclosure [Text Block]	Note 4. The following table summarizes our debt obligations outstanding as of March 31, 2024 December 31, 2023 not 8, March 31, 2024 December 31, 2023 Current portion of debt: SBA Paycheck Protection Program loan $ 43 $ 43 Vehicle loan, current portion 13 13 SBA EIDL Loan, matures July 2053, current portion 10 10 Total current portion of debt $ 66 $ 66 Long-term debt: SBA Paycheck Protection Program loans, matures May 2025 $ 97 $ 97 Vehicle loan, matures March 2029 51 55 SBA EIDL Loan, matures July 2053 136 137 Total long-term debt, net of current $ 284 $ 289 Total $ 350 $ 355 For the three March 31, 2024 For the three March 31, 2023 Vehicle loan On February 7, 2023, March 7, 2029. March 31, 2024, SBA Program Loans On February 7, 2022, March 31, 2024 On May 12, 2022, May 2025. In July 2020, July 2053. March 31, 2024,

Note 5 - Share-based Compensati

Note 5 - Share-based Compensation	3 Months Ended
Note 5 - Share-based Compensation	Mar. 31, 2024
Notes to Financial Statements
Compensation and Employee Benefit Plans [Text Block]	Note 5. Issuance of Common Stock in exchange for Services Payment of Officer Salaries No three March, 31, 2024. On March 31, 2023, Shares issued to Officers are unvested at the date of grant and subject to a lock-up agreement restricting vesting and sale until the earlier of (i) the consummation of a sale (in a single transaction or in a series of related transactions) of BioLargo by means of a sale of (a) a majority of the then outstanding common stock of BioLargo (whether by merger, consolidation, sale or transfer of common stock, reorganization, recapitalization or otherwise) or (b) all or substantially all of the assets of BioLargo; and (ii) the successful commercialization of BioLargo’s products or technologies as demonstrated by its receipt of at least $3,000,000 in cash, or the recognition of $3,000,000 in revenue, over a 12 Payment of Consultant and Vendor Fees On March 31, 2024 On March 31, 2023, All of these offerings and sales were made in reliance on the exemption from registration contained in Section 4 2 not Stock Option Expense During the three March 31, 2024 2018 three March 31, 2024 2023. 2018 On June 22, 2018, 2018 “2018 may June 22, 2028. 2018 January 1 st March 31, 2024 Activity for our stock options under the 2018 three March 31, 2024 2023 Options outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic Value(1) Balance, December 31, 2022 28,484,549 $ 0.19 Granted 1,320,498 0.20 Balance, March 31, 2023 29,805,047 0.19 7.5 678,000 Balance, December 31, 2023 41,108,448 $ 0.19 Granted 1,547,938 $ 0.30 Balance, March 31, 2024 42,656,386 $ 0.19 7.4 $ 5,909,000 Unvested (5,025,052 ) $ 0.20 Vested, March 31, 2024 37,631,334 $ 0.19 7.4 $ 4,455,000 ( 1 March 31, 2024 The options granted to purchase 1,547,938 shares during the three March 31, 2024 As of March 31, 2024, The options granted to purchase 1,320,498 shares during the three March 31, 2023 four 2007 On September 7, 2007, April 29, 2011, 2007 “2007 may September 7, 2017. September 2017, Activity for our stock options under the 2007 three March 31, 2024 2023 Options Outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic Value(1) Balance, December 31, 2022 1,904,085 $ 0.56 Expired — — Balance, March 31, 2023 1,904,085 $ 0.56 1.5 $ — Balance, December 31, 2023 1,564,085 $ 0.61 Expired — — Balance, March 31, 2024 1,564,085 $ 0.61 0.9 $ — ( 1 March 31, 2024 Non-Plan Options Activity of our non-plan stock options issued for the three March 31, 2024 2023 Non-plan Options outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic Value(1) Balance, December 31, 2022 19,023,829 $ 0.39 Granted 48,804 $ 0.20 Balance, March 31, 2023 19,072,633 $ 0.39 4.1 $ 88,000 Balance, December 31, 2023 17,375,044 $ 0.39 Expired (275,376 ) $ 0.44 Balance, March 31, 2024 17,099,668 $ 0.39 3.1 $ 695,000 Unvested (1,056,177 ) $ 0.26 Vested, March 31, 2024 16,043,491 $ 0.40 3.1 $ 437,000 ( 1 March 31, 2024 During the three March 31, 2024 not March 31, 2024, four During the three March 31, 2023,

Note 6 - Warrants

Note 6 - Warrants	3 Months Ended
Note 6 - Warrants	Mar. 31, 2024
Notes to Financial Statements
Warrants [Text Block]	Note 6. We have certain warrants outstanding to purchase our common stock, at various prices, as described in the following table: Warrants outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic value(1) Balance, December 31, 2022 49,023,398 $ 0.26 Granted 7,512,000 $ 0.25 Expired (4,684,986 ) $ 0.21 Balance, March 31, 2023 51,850,412 $ 0.26 $ 2.4 $ 122,000 Balance, December 31, 2023 51,590,300 $ 0.27 Granted 3,218,422 $ 0.25 Expired (406,278 ) $ 0.37 Exercised (600,000 ) $ 0.25 Balance, March 31, 2024 53,802,444 $ 0.26 $ 2.0 $ 4,021,000 ( 1 March 31, 2024 Warrants issued in Unit Offerings During the three March 31, 2024 six five 3 five During the three March 31, 2023, 3 six five Warrant issued in conjunction with amendment to note payable On March 6, 2023, 4, March 1, 2023”) five Warrant Fair Value We use the Black-Scholes option pricing model to determine the relative fair value of warrants issued in conjunction with debt instruments, common stock, and for services. With respect to debt instruments, relative fair value is amortized over the life of the warrant. The principal assumptions we used in applying the Black-Scholes model were as follows: 2024 2023 Risk free interest rate 4.04 – 5.28 % 3.88 – 4.27 % Expected volatility 64 87 % 40 95 % Expected dividend yield — — Forfeiture rate — — Expected life in years .5 – 5 .5 – 5 The risk-free interest rate is based on U.S. Treasury yields in effect at the time of grant. Expected volatilities are based on historical volatility of our common stock. The expected life in years is based on the contract term of the warrant.

Note 7 - Accounts Payable and A

Note 7 - Accounts Payable and Accrued Expenses	3 Months Ended
Note 7 - Accounts Payable and Accrued Expenses	Mar. 31, 2024
Notes to Financial Statements
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	Note 7. As of March 31, 2024 Category BioLargo ONM BLEST Canada BETI BEST Intercompany amounts Totals Accounts payable $ 200 $ 1,357 $ 62 $ 44 $ 24 $ — $ (24 ) $ 1,663 Accrued payroll 13 39 22 — — 3 — 77 Total $ 1,740 As of December 31, 2023 Category BioLargo ONM BLEST Canada BETI BEST Intercompany amounts Totals Accounts payable $ 163 $ 964 $ 34 $ 93 40 $ — $ (82 ) $ 1,212 Accrued payroll 49 86 116 — — — — 251 Accrued interest 25 — — — — — — 25 Total $ 1,488 See Note 8, Amounts owed by ONM Environmental are comprised primarily of amounts owed to suppliers for goods and were not

Note 8 - Noncontrolling Interes

Note 8 - Noncontrolling Interest - Clyra Medical	3 Months Ended
Note 8 - Noncontrolling Interest - Clyra Medical	Mar. 31, 2024
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 8. Clyra Medical As discussed in Note 2 Debt Obligations of Clyra Medical Promissory Note On April 8, 2022, April 8, 2024, may March 31, 2024 December 31, 2023 Line of Credit On June 30, 2020, may On December 13, 2022, September 30, 2024, January 9, 2023, As of March 31, 2024 December 31, 2023 Equity Transactions On December 15, 2023, one 1 During the three March 31, 2024, no As of March 31, 2024 December 31, 2023 March 31, 2024 December 31, 2023, BioLargo Conversion of Intercompany Balances In July 2023, Sales of Common Stock During the three March 31, 2024, February 28, 2027, five During the three March 31, 2023, not Sales of Series A Preferred Stock The Series A Preferred Stock offering closed in October 2023. no one may March 31, 2024 December 31, 2023, may 20% 30 may January 1, 2025, June 30, 2026. Clyra Stock Options Clyra Options Outstanding Weighted average price per share Weighted average remaining life Balance, December 31, 2022 1,583,329 $ 0.06 Granted 42,582 1.48 Balance, March 31, 2023 1,625,911 $ 0.09 7.5 Balance, December 31, 2023 1,478,922 $ 0.06 Granted 25,833 $ 4.05 Balance, March 31, 2024 1,504,755 $ 0.38 6.8 Unvested (12,300 ) $ 2.71 Balance, March 31, 2024 1,492,455 $ 0.36 6.8 Clyra issues options to its employees and consultants in lieu of compensation owed on a regular basis. The fair value of the options issued totaled $59,000 in the three March 31, 2024 three March 31, 2023 three March 31, 2024 2023, ant of $4.50 and $2. 71 no March 31, 2024 December 31, 2023 Risk free interest rate 4.16 % 3.48 - 4.45 % Expected volatility 49 % 49 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10 Clyra Warrants Clyra warrants outstanding Weighted average price per share Weighted average remaining life Balance, December 31, 2022 207,513 $ 3.72 Granted 72,581 $ 3.72 Balance, March 31, 2023 280,094 $ 3.72 3.5 Balance, December 31, 2023 749,911 $ 3.74 Granted 47,500 $ 7.50 Balance, March 31, 2024 797,411 $ 3.96 2.7 As part of the Clyra unit offering, it issued three Accounts Payable and Accrued Expenses At March 31, 2024 December 31, 2023 Category 2024 2023 Accounts payable $ 417 $ 135 Accrued dividend 328 $ 242 Accrued payroll 12 7 Accrued interest 15 13 Total $ 772 $ 397

Note 9 - BioLargo Engineering,

Note 9 - BioLargo Engineering, Science and Technologies, LLC	3 Months Ended
	Mar. 31, 2024
Notes to Financial Statements
Wholly-Owned Subsidiary [Text Block]	Note 9. In September 2017, three six two no five December 31, 2023 March 31, 2024,

Note 10 - BioLargo Energy Techn

Note 10 - BioLargo Energy Technologies, Inc.	3 Months Ended
Note 10 - BioLargo Energy Technologies, Inc.	Mar. 31, 2024
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 8. Clyra Medical As discussed in Note 2 Debt Obligations of Clyra Medical Promissory Note On April 8, 2022, April 8, 2024, may March 31, 2024 December 31, 2023 Line of Credit On June 30, 2020, may On December 13, 2022, September 30, 2024, January 9, 2023, As of March 31, 2024 December 31, 2023 Equity Transactions On December 15, 2023, one 1 During the three March 31, 2024, no As of March 31, 2024 December 31, 2023 March 31, 2024 December 31, 2023, BioLargo Conversion of Intercompany Balances In July 2023, Sales of Common Stock During the three March 31, 2024, February 28, 2027, five During the three March 31, 2023, not Sales of Series A Preferred Stock The Series A Preferred Stock offering closed in October 2023. no one may March 31, 2024 December 31, 2023, may 20% 30 may January 1, 2025, June 30, 2026. Clyra Stock Options Clyra Options Outstanding Weighted average price per share Weighted average remaining life Balance, December 31, 2022 1,583,329 $ 0.06 Granted 42,582 1.48 Balance, March 31, 2023 1,625,911 $ 0.09 7.5 Balance, December 31, 2023 1,478,922 $ 0.06 Granted 25,833 $ 4.05 Balance, March 31, 2024 1,504,755 $ 0.38 6.8 Unvested (12,300 ) $ 2.71 Balance, March 31, 2024 1,492,455 $ 0.36 6.8 Clyra issues options to its employees and consultants in lieu of compensation owed on a regular basis. The fair value of the options issued totaled $59,000 in the three March 31, 2024 three March 31, 2023 three March 31, 2024 2023, ant of $4.50 and $2. 71 no March 31, 2024 December 31, 2023 Risk free interest rate 4.16 % 3.48 - 4.45 % Expected volatility 49 % 49 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10 Clyra Warrants Clyra warrants outstanding Weighted average price per share Weighted average remaining life Balance, December 31, 2022 207,513 $ 3.72 Granted 72,581 $ 3.72 Balance, March 31, 2023 280,094 $ 3.72 3.5 Balance, December 31, 2023 749,911 $ 3.74 Granted 47,500 $ 7.50 Balance, March 31, 2024 797,411 $ 3.96 2.7 As part of the Clyra unit offering, it issued three Accounts Payable and Accrued Expenses At March 31, 2024 December 31, 2023 Category 2024 2023 Accounts payable $ 417 $ 135 Accrued dividend 328 $ 242 Accrued payroll 12 7 Accrued interest 15 13 Total $ 772 $ 397
BioLargo Energy Technologies, Inc (BETI) [Member]
Notes to Financial Statements
Noncontrolling Interest Disclosure [Text Block]	Note 10. BioLargo Energy Technologies, Inc. (“BETI”) was formed for the purpose of commercializing a proprietary sodium battery technology. BioLargo purchased 9,000,000 shares of its common stock upon its formation, and was its sole stockholder. During the three March 31, 2024 one three March 31, 2023, six one third As of March 31, 2024

Note 11 - Business Segment Info

Note 11 - Business Segment Information	3 Months Ended
Note 11 - Business Segment Information	Mar. 31, 2024
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	Note 11. BioLargo has six 1. ONM Environmental -- which sells odor and volatile organic control products and services, located in Westminster, California; 2. Clyra Medical Technologies (“Clyra Medical”) -- which develops and sells medical products based on our technologies, located in Tampa, Florida; 3. BioLargo Engineering (BLEST) -- which provides professional engineering services on a time and materials basis for outside clients and supports our internal operations as needed, located in Oak Ridge, Tennessee; 4. BioLargo Canada, Inc. (“Canada”) – the main hub of our scientists researching and developing our technologies, operating out of the University of Alberta, Edmonton, Canada; and 5. BioLargo Energy Technologies, Inc. (“BETI”) – which is developing our proprietary battery technology. 6. BioLargo Equipment Solutions & Technologies, Inc. (“BEST”) – which manages the sales and distribution of our water treatment products and related services. Other than ONM Environmental, none third The segment information for the three March 31, 2024 2023 Three Months Ended March 31, 2024 2023 Revenue ONM Environmental $ 4,575 $ 3,543 BLEST 356 363 Clyra Medical — 6 Intersegment revenue (171 ) (170 ) Total $ 4,760 $ 3,742 Stock option expense BioLargo corporate $ (429 ) $ (195 ) Clyra Medical (59 ) (61 ) Total $ (488 ) $ (256 ) Depreciation expense BioLargo corporate $ (10 ) $ (6 ) ONM Environmental (5 ) (4 ) BLEST (19 ) (2 ) Clyra Medical (2 ) (10 ) Total $ (36 ) $ (22 ) Research and development expense BioLargo corporate $ (314 ) $ (189 ) ONM Environmental — — BLEST (352 ) (245 ) BETI (80 ) (32 ) BioLargo Canada (80 ) (135 ) Clyra Medical (121 ) (134 ) Intersegment R&D 163 170 Total $ (784 ) $ (565 ) Operating income (loss) BioLargo corporate $ (1,244 ) $ (799 ) ONM Environmental 1,798 1,387 BLEST (445 ) (368 ) BETI (155 ) (87 ) BEST (66 ) — BioLargo Canada (105 ) (184 ) Clyra Medical (546 ) (426 ) Total $ (763 ) $ (477 ) Interest expense BioLargo corporate $ (3 ) $ (36 ) ONM Environmental (2 ) (2 ) Clyra Medical (7 ) (10 ) Total $ (12 ) $ (48 ) As of March 31, 2024 BioLargo ONM BLEST CLYRA BETI BEST Canada Elimination Total Tangible assets $ 1,079 $ 5,870 $ 734 $ 949 $ 65 $ — $ 38 $ — $ 8,735 Right of use operating lease 380 — 688 — — — — — 1,068 Investment in South Korean joint venture 18 — — — — — — — 18 Total $ 1,477 $ 5,870 $ 1,422 $ 949 $ 65 $ — $ 38 $ — $ 9,821 As of December 31, 2023 BioLargo ONM BLEST CLYRA BETI BEST Canada Elimination Total Tangible assets $ 942 $ 4,624 $ 1,083 $ 432 $ 4 $ — $ 50 $ (41 ) $ 7,094 Right of use operating lease 394 — 698 — — — — — 1,092 Investment in South Korean joint venture 19 — — — — — — — 19 Total $ 1,355 $ 4,624 $ 1,781 $ 432 $ 4 $ — $ 50 $ (41 ) $ 8,205

Note 12 - Leases

Note 12 - Leases	3 Months Ended
Note 12 - Leases	Mar. 31, 2024
Notes to Financial Statements
Lessor, Operating Leases [Text Block]	Note 12. Office Leases W e have long-term operating leases for office, industrial and laboratory space in Westminster, California, Oak Ridge, Tennessee, and Alberta, Canada. Payments made under operating leases are charged to the Consolidated Statement of Operations and Comprehensive Loss on a straight-line basis over the term of the operating lease agreement. Short-term leases less than one not three March 31, 2024 , rental expense was $88,000; three March 31, 2023 , rental expense was $83,000. The lease of our Westminster facility expires August 2024. four four December 31, 2023. one None not no March 31, 2024, seven As of December 31, 2023 , seven five BioLargo Year ending Corp / ONM BLEST Total December 31, 2024 122,000 154,000 276,000 December 31, 2025 125,000 157,000 282,000 December 31, 2026 129,000 160,000 289,000 December 31, 2027 133,000 163,000 296,000 December 31, 2028 79,000 166,000 245,000 Thereafter — 654,000 654,000 Total minimum lease payments $ 588,000 $ 1,454,000 $ 2,042,000 Less imputed interest (933,000 ) Total operating lease liability $ 1,109,000

Note 13 - Subsequent Events

Note 13 - Subsequent Events	3 Months Ended
Note 13 - Subsequent Events	Mar. 31, 2024
Notes to Financial Statements
Subsequent Events [Text Block]	Note 13. Sale of Stock for Cash From April 1, 2024, May 13, 2024, two six five 3 6 Exercise of Stock Options and Warrants From April 1, 2024, May 13, 2024, From April 1, 2024, May 13, 2024, Exchange of BETI common stock Each third April 1, 2024,

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024 shares
Insider Trading Arr Line Items
Material Terms of Trading Arrangement [Text Block]	5. Other Information Lincoln Park On December 13, 2022, entered $10.0 $0.00067 9B During the three March 31, 2024 766,175 $260,000
Rule 10b5-1 Arrangement Adopted [Flag]	false
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false
Trading Arrangement, Securities Aggregate Available Amount	766,175

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2024
Notes Tables
Schedule of Cash and Cash Equivalents [Table Text Block]	March 31, 2024 December 31, 2023 BioLargo, Inc. and subsidiaries $ 4,242 $ 3,142 Clyra Medical Technologies, Inc. 94 397 Total $ 4,336 $ 3,539
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	Three Months ended March 31, 2024 2023 Customer A 88 % 86 % March 31, 2024 December 31, 2023 Customer A 79 % 68 %
Schedule of Inventory, Current [Table Text Block]	March 31, 2024 December 31, 2023 Raw material $ 85 $ 79 Finished goods 166 74 Total $ 251 $ 153
Schedule of Other Assets, Noncurrent [Table Text Block]	March 31, 2024 December 31, 2023 Patents $ 34 $ 34 Security deposits 36 36 Total $ 70 $ 70
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2024 2023 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate — % 4.16 % 3.48 % 3.48 % Expected volatility — % 99 % 114 % 114 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years — 10 10 10

Note 4 - Debt Obligations (Tabl

Note 4 - Debt Obligations (Tables)	3 Months Ended
Note 4 - Debt Obligations (Tables)	Mar. 31, 2024
Notes Tables
Schedule of Debt [Table Text Block]	March 31, 2024 December 31, 2023 Current portion of debt: SBA Paycheck Protection Program loan $ 43 $ 43 Vehicle loan, current portion 13 13 SBA EIDL Loan, matures July 2053, current portion 10 10 Total current portion of debt $ 66 $ 66 Long-term debt: SBA Paycheck Protection Program loans, matures May 2025 $ 97 $ 97 Vehicle loan, matures March 2029 51 55 SBA EIDL Loan, matures July 2053 136 137 Total long-term debt, net of current $ 284 $ 289 Total $ 350 $ 355

Note 5 - Share-based Compensa_2

Note 5 - Share-based Compensation (Tables)	3 Months Ended
Note 5 - Share-based Compensation (Tables)	Mar. 31, 2024
Notes Tables
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Options outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic Value(1) Balance, December 31, 2022 28,484,549 $ 0.19 Granted 1,320,498 0.20 Balance, March 31, 2023 29,805,047 0.19 7.5 678,000 Balance, December 31, 2023 41,108,448 $ 0.19 Granted 1,547,938 $ 0.30 Balance, March 31, 2024 42,656,386 $ 0.19 7.4 $ 5,909,000 Unvested (5,025,052 ) $ 0.20 Vested, March 31, 2024 37,631,334 $ 0.19 7.4 $ 4,455,000 Options Outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic Value(1) Balance, December 31, 2022 1,904,085 $ 0.56 Expired — — Balance, March 31, 2023 1,904,085 $ 0.56 1.5 $ — Balance, December 31, 2023 1,564,085 $ 0.61 Expired — — Balance, March 31, 2024 1,564,085 $ 0.61 0.9 $ — Non-plan Options outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic Value(1) Balance, December 31, 2022 19,023,829 $ 0.39 Granted 48,804 $ 0.20 Balance, March 31, 2023 19,072,633 $ 0.39 4.1 $ 88,000 Balance, December 31, 2023 17,375,044 $ 0.39 Expired (275,376 ) $ 0.44 Balance, March 31, 2024 17,099,668 $ 0.39 3.1 $ 695,000 Unvested (1,056,177 ) $ 0.26 Vested, March 31, 2024 16,043,491 $ 0.40 3.1 $ 437,000

Note 6 - Warrants (Tables)

Note 6 - Warrants (Tables)	3 Months Ended
Note 6 - Warrants (Tables)	Mar. 31, 2024
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Warrants outstanding Weighted average price per share Weighted average remaining life Aggregate intrinsic value(1) Balance, December 31, 2022 49,023,398 $ 0.26 Granted 7,512,000 $ 0.25 Expired (4,684,986 ) $ 0.21 Balance, March 31, 2023 51,850,412 $ 0.26 $ 2.4 $ 122,000 Balance, December 31, 2023 51,590,300 $ 0.27 Granted 3,218,422 $ 0.25 Expired (406,278 ) $ 0.37 Exercised (600,000 ) $ 0.25 Balance, March 31, 2024 53,802,444 $ 0.26 $ 2.0 $ 4,021,000
Schedule Of Assumptions Used To Determine Fair Value Of Warrants [Table Text Block]	2024 2023 Risk free interest rate 4.04 – 5.28 % 3.88 – 4.27 % Expected volatility 64 87 % 40 95 % Expected dividend yield — — Forfeiture rate — — Expected life in years .5 – 5 .5 – 5

Note 7 - Accounts Payable and_2

Note 7 - Accounts Payable and Accrued Expenses (Tables)	3 Months Ended
Note 7 - Accounts Payable and Accrued Expenses (Tables)	Mar. 31, 2024
Notes Tables
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category BioLargo ONM BLEST Canada BETI BEST Intercompany amounts Totals Accounts payable $ 200 $ 1,357 $ 62 $ 44 $ 24 $ — $ (24 ) $ 1,663 Accrued payroll 13 39 22 — — 3 — 77 Total $ 1,740 Category BioLargo ONM BLEST Canada BETI BEST Intercompany amounts Totals Accounts payable $ 163 $ 964 $ 34 $ 93 40 $ — $ (82 ) $ 1,212 Accrued payroll 49 86 116 — — — — 251 Accrued interest 25 — — — — — — 25 Total $ 1,488

Note 8 - Noncontrolling Inter_2

Note 8 - Noncontrolling Interest - Clyra Medical (Tables)	3 Months Ended
Note 8 - Noncontrolling Interest - Clyra Medical (Tables)	Mar. 31, 2024
Notes Tables
Schedule of Other Ownership Interests [Table Text Block]	Clyra Options Outstanding Weighted average price per share Weighted average remaining life Balance, December 31, 2022 1,583,329 $ 0.06 Granted 42,582 1.48 Balance, March 31, 2023 1,625,911 $ 0.09 7.5 Balance, December 31, 2023 1,478,922 $ 0.06 Granted 25,833 $ 4.05 Balance, March 31, 2024 1,504,755 $ 0.38 6.8 Unvested (12,300 ) $ 2.71 Balance, March 31, 2024 1,492,455 $ 0.36 6.8
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2024 2023 Non Plan 2018 Plan Non Plan 2018 Plan Risk free interest rate — % 4.16 % 3.48 % 3.48 % Expected volatility — % 99 % 114 % 114 % Expected dividend yield — — — — Forfeiture rate — — — — Life in years — 10 10 10
Warrants Outstanding for Noncontrolling Interest [Table Text Block]	Clyra warrants outstanding Weighted average price per share Weighted average remaining life Balance, December 31, 2022 207,513 $ 3.72 Granted 72,581 $ 3.72 Balance, March 31, 2023 280,094 $ 3.72 3.5 Balance, December 31, 2023 749,911 $ 3.74 Granted 47,500 $ 7.50 Balance, March 31, 2024 797,411 $ 3.96 2.7
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category BioLargo ONM BLEST Canada BETI BEST Intercompany amounts Totals Accounts payable $ 200 $ 1,357 $ 62 $ 44 $ 24 $ — $ (24 ) $ 1,663 Accrued payroll 13 39 22 — — 3 — 77 Total $ 1,740 Category BioLargo ONM BLEST Canada BETI BEST Intercompany amounts Totals Accounts payable $ 163 $ 964 $ 34 $ 93 40 $ — $ (82 ) $ 1,212 Accrued payroll 49 86 116 — — — — 251 Accrued interest 25 — — — — — — 25 Total $ 1,488
Clyra Medical [Member]
Notes Tables
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	March 31, 2024 December 31, 2023 Risk free interest rate 4.16 % 3.48 - 4.45 % Expected volatility 49 % 49 % Expected dividend yield — — Forfeiture rate — — Expected life in years 10 10
Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]	Category 2024 2023 Accounts payable $ 417 $ 135 Accrued dividend 328 $ 242 Accrued payroll 12 7 Accrued interest 15 13 Total $ 772 $ 397

Note 11 - Business Segment In_2

Note 11 - Business Segment Information (Tables)	3 Months Ended
Note 11 - Business Segment Information (Tables)	Mar. 31, 2024
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Three Months Ended March 31, 2024 2023 Revenue ONM Environmental $ 4,575 $ 3,543 BLEST 356 363 Clyra Medical — 6 Intersegment revenue (171 ) (170 ) Total $ 4,760 $ 3,742 Stock option expense BioLargo corporate $ (429 ) $ (195 ) Clyra Medical (59 ) (61 ) Total $ (488 ) $ (256 ) Depreciation expense BioLargo corporate $ (10 ) $ (6 ) ONM Environmental (5 ) (4 ) BLEST (19 ) (2 ) Clyra Medical (2 ) (10 ) Total $ (36 ) $ (22 ) Research and development expense BioLargo corporate $ (314 ) $ (189 ) ONM Environmental — — BLEST (352 ) (245 ) BETI (80 ) (32 ) BioLargo Canada (80 ) (135 ) Clyra Medical (121 ) (134 ) Intersegment R&D 163 170 Total $ (784 ) $ (565 ) Operating income (loss) BioLargo corporate $ (1,244 ) $ (799 ) ONM Environmental 1,798 1,387 BLEST (445 ) (368 ) BETI (155 ) (87 ) BEST (66 ) — BioLargo Canada (105 ) (184 ) Clyra Medical (546 ) (426 ) Total $ (763 ) $ (477 ) Interest expense BioLargo corporate $ (3 ) $ (36 ) ONM Environmental (2 ) (2 ) Clyra Medical (7 ) (10 ) Total $ (12 ) $ (48 ) As of March 31, 2024 BioLargo ONM BLEST CLYRA BETI BEST Canada Elimination Total Tangible assets $ 1,079 $ 5,870 $ 734 $ 949 $ 65 $ — $ 38 $ — $ 8,735 Right of use operating lease 380 — 688 — — — — — 1,068 Investment in South Korean joint venture 18 — — — — — — — 18 Total $ 1,477 $ 5,870 $ 1,422 $ 949 $ 65 $ — $ 38 $ — $ 9,821 As of December 31, 2023 BioLargo ONM BLEST CLYRA BETI BEST Canada Elimination Total Tangible assets $ 942 $ 4,624 $ 1,083 $ 432 $ 4 $ — $ 50 $ (41 ) $ 7,094 Right of use operating lease 394 — 698 — — — — — 1,092 Investment in South Korean joint venture 19 — — — — — — — 19 Total $ 1,355 $ 4,624 $ 1,781 $ 432 $ 4 $ — $ 50 $ (41 ) $ 8,205

Note 12 - Leases (Tables)

Note 12 - Leases (Tables)	3 Months Ended
Note 12 - Leases (Tables)	Mar. 31, 2024
Notes Tables
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]	BioLargo Year ending Corp / ONM BLEST Total December 31, 2024 122,000 154,000 276,000 December 31, 2025 125,000 157,000 282,000 December 31, 2026 129,000 160,000 289,000 December 31, 2027 133,000 163,000 296,000 December 31, 2028 79,000 166,000 245,000 Thereafter — 654,000 654,000 Total minimum lease payments $ 588,000 $ 1,454,000 $ 2,042,000 Less imputed interest (933,000 ) Total operating lease liability $ 1,109,000

Note 1 - Business and Organiz_2

Note 1 - Business and Organization (Details Textual)	3 Months Ended
Note 1 - Business and Organization (Details Textual)	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2017
Number of Wholly-Owned Subsidiaries	5
Number of Partially-Owned Subsidiaries	3
Revenue from Contract with Customer, Including Assessed Tax	$ 4,760,000	$ 3,742,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(775,000)	(494,000)
Net Cash Provided by (Used in) Operating Activities	481,000	(43,000)
Assets, Current	7,176,000		$ 6,362,000
Cash and Cash Equivalents, at Carrying Value	4,336,000		3,539,000
Liabilities, Current	3,404,000		$ 2,710,000
Working Capital (Deficit)	3,772,000
Net Cash Provided by (Used in) Operating Activities	481,000	(43,000)
Stock Issued During Period, Value, New Issues	488,000	800,000
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	52,000	$ 225,000
Conversion of Assets, Contingency, Accounts Receivable to Cash	2,473,000
The 2020 Unit Offering [Member]
Stock Issued During Period, Value, New Issues	228,000
Clyra Medical Common Stock [Member]
Proceeds from Issuance or Sale of Equity	475,000
Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Value, New Issues	$ 260,000
Clyra Medical Technologies [Member]
Subsidiary, Ownership Percentage, Parent	53%
BioLargo Engineering, Science & Technologies, LLC [Member]
Subsidiary, Ownership Percentage, Parent	82%			100%
BioLargo Energy Technologies, Inc (BETI) [Member]
Subsidiary, Ownership Percentage, Parent	96%
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	$ 50,000

Note 2 - Summary of Significa_3

Note 2 - Summary of Significant Accounting Policies (Details Textual)		3 Months Ended		12 Months Ended
	Mar. 20, 2020 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2022	Oct. 22, 2021 USD ($)
Accounts Receivable, Allowance for Credit Loss, Current		$ 84,000		$ 84,000
Inventory Valuation Reserves		212,000		212,000
Number of Patents Acquired							3
Income (Loss) from Equity Method Investments		(1,000)	$ (6,000)
Contract with Customer, Liability		261,000		303,000
Contract with Customer, Liability, Revenue Recognized		42,000
Customer Deposit Liability, Current		226,000		117,000
Revenue Recognized from Customer Deposits		4,000
Unrecognized Tax Benefits		$ 0		0
Operating Lease, Weighted Average Discount Rate, Percent		18%
Operating Lease, Right-of-Use Asset		$ 1,068,000		1,092,000
Operating Lease, Liability		$ 1,090,000		1,109,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		10 years
Canadian Government Grants [Member] \| Minimum [Member]
Grant Term (Month)		6 months
Canadian Government Grants [Member] \| Maximum [Member]
Grant Term (Month)		18 months
ONM [Member]
Customer Deposit Liability, Current		$ 116,000			$ 4,000
CANADA
Customer Deposit Liability, Current		$ 110,000		$ 113,000
Odin Co Ltd [Member]
Payments to Acquire Interest in Joint Venture	$ 100,000
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	40%	40%
Income (Loss) from Equity Method Investments		$ 1,000	$ 6,000
Odin Co Ltd [Member] \| Tomorrow Water [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	30%
Odin Co Ltd [Member] \| BKT and Tomorrow Water [Member]
Payments to Acquire Interest in Joint Venture	$ 150,000
Clyra Medical Technologies [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner				47%		47%
BioLargo Engineering, Science & Technologies, LLC [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner				23%		18%
BioLargo Energy Technologies, Inc (BETI) [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner				4%
Patents [Member]
Intangible Assets, Net (Excluding Goodwill), Total							$ 34,000
Customer Concentration Risk [Member] \| Accounts Receivable [Member]
Number of Major Customers				1
Customer Concentration Risk [Member] \| Accounts Receivable [Member] \| One Customer [Member]
Concentration Risk, Percentage				10%

Note 2 - Summary of Significa_4

Note 2 - Summary of Significant Accounting Policies - Summary of Cash Balances (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Cash and Cash Equivalents, at Carrying Value	$ 4,336,000	$ 3,539,000
Parent Company [Member]
Cash and Cash Equivalents, at Carrying Value	4,242,000	3,142,000
Noncontrolling Interest [Member]
Cash and Cash Equivalents, at Carrying Value	$ 94,000	$ 397,000

Note 2 - Summary of Significa_5

Note 2 - Summary of Significant Accounting Policies - Credit Concentration (Details) - Customer A [Member] - Customer Concentration Risk [Member]	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Accounts Receivable [Member]
Credit concentration	79%		68%
Revenue from Contract with Customer Benchmark [Member]
Credit concentration	88%	86%

Note 2 - Summary of Significa_6

Note 2 - Summary of Significant Accounting Policies - Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Raw material	$ 85	$ 79
Finished goods	166	74
Total	$ 251	$ 153

Note 2 - Summary of Significa_7

Note 2 - Summary of Significant Accounting Policies - Other Non-current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Patents	$ 34	$ 34
Security deposits	36	36
Total	$ 70	$ 70

Note 2 - Summary of Significa_8

Note 2 - Summary of Significant Accounting Policies - Stock Options, Valuation Assumptions (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Non Plan [Member]
Expected volatility	99%
Expected dividend yield	0%
Forfeiture rate	0%
Expected life in years (Year)	10 years
Non Plan [Member] \| Minimum [Member]
Risk free interest rate	0%
Non Plan [Member] \| Maximum [Member]
Risk free interest rate		3.48%
Expected volatility		114%
Expected life in years (Year)		10 years
2018 Equity Incentive Plan [Member] \| Minimum [Member]
Risk free interest rate		3.48%
Expected volatility		114%
Expected life in years (Year)		10 years

Note 3 - Sale of Stock for Ca_2

Note 3 - Sale of Stock for Cash (Details Textual)	3 Months Ended
Note 3 - Sale of Stock for Cash (Details Textual)	Mar. 31, 2024 USD ($) shares	Mar. 31, 2023 USD ($) shares	Dec. 13, 2022 USD ($)
Proceeds from Issuance of Common Stock	$ 488,000	$ 800,000
Warrants Issued with 2020 Unit Offering [Member] \| Minimum [Member]
Warrants and Rights Outstanding, Term (Year)	6 years
Warrants Issued with 2020 Unit Offering [Member] \| Maximum [Member]
Warrants and Rights Outstanding, Term (Year)	5 years
The 2020 Unit Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) \| shares	1,394,173	3,656,000
Proceeds From Issuance of Common Stock, Gross	$ 267,000	$ 695,000
Proceeds from Issuance of Common Stock	$ 228,000
Number of Accredited Investors	5	11
Lincoln Park Capital Fund, LLC [Member]
Stock Purchase Agreement, Maximum Amount of Common Stock			$ 10,000,000
Stock Issued During Period, Shares, New Issues (in shares) \| shares	766,175	545,402
Proceeds From Issuance of Common Stock, Gross	$ 260,000	$ 105,000

Note 4 - Debt Obligations (Deta

Note 4 - Debt Obligations (Details Textual) - USD ($)			1 Months Ended	3 Months Ended
Note 4 - Debt Obligations (Details Textual) - USD ($)	Feb. 07, 2023	Feb. 07, 2022	Jul. 31, 2020	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	May 12, 2022
Interest Expense, Debt				$ 12,000	$ 48,000
Paycheck Protection Program CARES Act [Member] \| ONM [Member]
Extinguishment of Debt, Amount		$ 174,000
Proceeds from Issuance of Debt		$ 217,000
Long-Term Debt						$ 43,000
Paycheck Protection Program CARES Act [Member] \| BioLargo Engineering, Science & Technologies, LLC [Member]
Long-Term Debt							$ 97,000
Economic Injury Disaster Loan [Member] \| ONM [Member]
Debt Instrument, Face Amount			$ 150,000
Debt Instrument, Interest Rate, Stated Percentage			3.75%
Debt Instrument, Periodic Payment			$ 700
Debt Instrument, Outstanding Balance				146,000
Vehicle Loan [Member]
Debt Instrument, Face Amount	$ 80,000
Debt Instrument, Interest Rate, Stated Percentage	5.29%
Debt Instrument, Periodic Payment	$ 1,000
Debt Instrument, Outstanding Balance				$ 64,000

Note 4 - Debt Obligations - Sch

Note 4 - Debt Obligations - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Total current portion of debt	$ 66	$ 66
Total long-term debt, net of current	284	289
Total	350	355
Vehicle Loan [Member]
Long-term debt, current	13	13
Total long-term debt, net of current	51	55
Paycheck Protection Program CARES Act [Member]
SBA Paycheck Protection Program loan	43	43
SBA Paycheck Protection Program loans, matures May 2025	97	97
Economic Injury Disaster Loan [Member]
Long-term debt, current	10	10
Total long-term debt, net of current	$ 136	$ 137

Note 5 - Share-based Compensa_3

Note 5 - Share-based Compensation (Details Textual) - USD ($)				3 Months Ended
	Mar. 31, 2023	Jun. 22, 2018	Sep. 07, 2017	Mar. 31, 2024	Mar. 31, 2023
Stock Issued During Period, Value, Issued for Services				$ 83,000	$ 207,000
Share Price (in dollars per share)				$ 0.35
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				0
Remaining Stock Option Plan Expense				$ 1,056,000
Stock Option Plan Expense, Period of Recognition (Year)				4 years
2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)		10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Per Year (in shares)		2,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)				52,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)				9,343,614
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				1,547,938	1,320,498
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount				$ 5,025,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)				4 years
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)				$ 0.3	$ 0.2
Equity Incentive Plan 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
Non Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					48,804
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)					$ 0.2
Share-Based Payment Arrangement, Option [Member] \| Clyra Medical Technologies [Member]
Share-Based Payment Arrangement, Expense				$ 59,000	$ 61,000
Selling, General and Administrative Expenses [Member]
Share-Based Payment Arrangement, Expense				$ 488,000	$ 256,000
Officer [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)	30,747			0
Stock Issued During Period, Value, Issued for Services	$ 6,000
Shares Issued, Price Per Share (in dollars per share)	$ 0.2				$ 0.2
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Minimum Cash Amount Receipt				$ 3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Minimum Revenue Required				$ 3,000,000
Consultants [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)				250,639	899,743
Stock Issued During Period, Value, Issued for Services				$ 83,000	$ 201,000
Shares Issued, Price Per Share (in dollars per share)	$ 0.2			$ 0.35	$ 0.2
Board of Directors, Employees, and Consultants [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				1,547,938
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value				$ 418,000
Board of Directors, Employees, and Consultants [Member] \| 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				544,841
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value				$ 173,000
Board Of Directors [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				267,746
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value				$ 85,000
Board Of Directors [Member] \| 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					347,730
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value					$ 65,000
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)					$ 0.2
Employees [Member] \| Employee Retention Program [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				735,351	570,204
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value				$ 160,000	$ 108,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)					4 years
Employees [Member] \| Employee Retention Program [Member] \| Maximum [Member]
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)					$ 0.2
Officer, Board of Directors, Employees, and a Consultant [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					1,320,498
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value					$ 248,000
Employees and Consultants [Member] \| 2018 Equity Incentive Plan [Member]
Stock Issued During Period, Value, Issued for Services					$ 19,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					102,564
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)					$ 0.2
Chief Financial Officer [Member] \| 2018 Equity Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					300,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Fair Value					$ 56,000
Vendors [Member] \| Non Plan [Member]
Share-Based Payment Arrangement, Expense					$ 9,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)					48,804
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)					$ 0.2

Note 5 - Share-based Compensa_4

Note 5 - Share-based Compensation - Stock Options (Details) - USD ($)		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Options outstanding, Granted (in shares)		0
2018 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		41,108,448	28,484,549
Weighted average exercise price, balance (in dollars per share)		$ 0.19	$ 0.19
Options outstanding, Granted (in shares)		1,547,938	1,320,498
Weighted average exercise price, Granted (in dollars per share)		$ 0.3	$ 0.2
Weighted average remaining term, Outstanding (Year)		7 years 4 months 24 days	7 years 6 months
Aggregate intrinsic Value, Balance		$ 5,909,000	$ 678,000	[1]
Options outstanding, balance (in shares)		42,656,386	29,805,047
Weighted average exercise price, balance (in dollars per share)		$ 0.19	$ 0.19
Unvested (in shares)		(5,025,052)
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.2
Options outstanding, Vested (in shares)		37,631,334
Weighted average exercise price, Vested (in dollars per share)		$ 0.19
Weighted average remaining term, Vested (Year)		7 years 4 months 24 days
Aggregate intrinsic value, Vested	[1]	$ 4,455,000
The 2007 Equity Incentive Plan [Member]
Options outstanding, balance (in shares)		1,564,085	1,904,085
Weighted average remaining term, Outstanding (Year)		10 months 24 days	1 year 6 months
Options outstanding, balance (in shares)		1,564,085	1,904,085
Options outstanding, Expired (in shares)		0	0
The 2007 Equity Incentive Plan [Member] \| Minimum [Member]
Weighted average exercise price, balance (in dollars per share)		$ 0.61	$ 0.56
Weighted average exercise price, balance (in dollars per share)		0.61	0.56
Weighted average exercise price per share, Expired (in dollars per share)		$ 0	$ 0
Non Plan [Member]
Options outstanding, balance (in shares)		17,375,044	19,023,829
Weighted average exercise price, balance (in dollars per share)		$ 0.39	$ 0.39
Options outstanding, Granted (in shares)			48,804
Weighted average exercise price, Granted (in dollars per share)			$ 0.2
Weighted average remaining term, Outstanding (Year)		3 years 1 month 6 days	4 years 1 month 6 days
Options outstanding, balance (in shares)		17,099,668	19,072,633
Weighted average exercise price, balance (in dollars per share)		$ 0.39	$ 0.39
Unvested (in shares)		(1,056,177)
Weighted average exercise price per share, unvested (in dollars per share)		$ 0.26
Options outstanding, Vested (in shares)		16,043,491
Weighted average exercise price, Vested (in dollars per share)		$ 0.4
Weighted average remaining term, Vested (Year)		3 years 1 month 6 days
Aggregate intrinsic value, Vested		$ 437,000
Options outstanding, Expired (in shares)		(275,376)
Weighted average exercise price per share, Expired (in dollars per share)		$ 0.44
Aggregate intrinsic value, balance		$ 695,000	$ 88,000	[1]

[1]Aggregate intrinsic value based on closing common stock price of $0.35 at March 31, 2024.

Note 6 - Warrants (Details Text

Note 6 - Warrants (Details Textual) - USD ($)	Mar. 31, 2024	Mar. 31, 2023		Mar. 06, 2023
Share Price (in dollars per share)	$ 0.35
Warrants and Rights Outstanding	$ 4,021,000	$ 122,000	[1]
Note Payable, Maturing March 8, 2023 [Member]
Debt Instrument, Face Amount				$ 50,000
Six-month Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Year)	6 months	6 months
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	1,394,737	3,656,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.23	$ 0.23
Five-year Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Year)	5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	1,394,737
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.29
Five Year Warrants in Connection with the 2020 Unit Offering, Commissions [Member]
Warrants and Rights Outstanding, Term (Year)	5 years
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.19
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	428,948
Warrants and Rights Outstanding, Fair Value	$ 201,000
Five-month Warrants in Connection With the 2020 Unit Offering [Member]
Warrants and Rights Outstanding, Term (Year)		5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		3,656,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.29
Warrants and Rights Outstanding, Fair Value		$ 1,097,000
Warrants Issued in Connection with Conversion of Interest on Note Payable Maturing March 8, 2023 [Member]
Warrants and Rights Outstanding, Term (Year)				5 years
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.21
Warrants and Rights Outstanding				$ 30,000

[1]Aggregate intrinsic value based on closing common stock price of $0.35 at March 31, 2024.

Note 6 - Warrants - Warrants Ou

Note 6 - Warrants - Warrants Outstanding (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Warrants outstanding, balance (in shares)	51,590,300	49,023,398
Warrants outstanding, Granted (in shares)	3,218,422	7,512,000
Warrants outstanding, Expired (in shares)	(406,278)	(4,684,986)
Weighted average remaining life, balance (Year)	2 years	2 years 4 months 24 days
Balance, aggregate intrinsic value	$ 4,021,000	$ 122,000	[1]
Warrants outstanding, Exercised (in shares)	(600,000)
Warrants outstanding, balance (in shares)	53,802,444	51,850,412
Weighted Average [Member]
Weighted average price, balance (in dollars per share)	$ 0.27	$ 0.26
Weighted average price, Granted (in dollars per share)	0.25	0.25
Weighted average price, Expired (in dollars per share)	0.37	0.21
Weighted average price, Exercised (in dollars per share)	0.25
Weighted average price, balance (in dollars per share)	$ 0.26	$ 0.26

[1]Aggregate intrinsic value based on closing common stock price of $0.35 at March 31, 2024.

Note 6 - Warrants - Assumptions

Note 6 - Warrants - Assumptions Used to Determine Fair Value of Warrants (Details) - Measurement Input, Risk Free Interest Rate [Member]	Mar. 31, 2024	Dec. 31, 2023
Minimum [Member]
Risk free interest rate	0.0404	0.0388
Maximum [Member]
Risk free interest rate	0.0528	0.0427

Note 7 - Accounts Payable and_3

Note 7 - Accounts Payable and Accrued Expenses - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounts payable	$ 1,663	$ 1,212
Accrued payroll	77	251
Total	1,740	1,488
Accrued interest		25
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Accounts payable	200	163
Accrued payroll	13	49
Accrued interest		25
Operating Segments [Member] \| Odor-No-More [Member]
Accounts payable	1,357	964
Accrued payroll	39	86
Accrued interest		0
Operating Segments [Member] \| BLEST [Member]
Accounts payable	62	34
Accrued payroll	22	116
Accrued interest		0
Operating Segments [Member] \| BioLargo Canada [Member]
Accounts payable	44	93
Accrued payroll	0	0
Accrued interest		0
Operating Segments [Member] \| BioLargo Energy Technologies, Inc (BETI) [Member]
Accounts payable	24	40
Accrued payroll	0	0
Accrued interest		0
Operating Segments [Member] \| BEST [Member]
Accounts payable	0	0
Accrued payroll	3	0
Accrued interest		0
Consolidation, Eliminations [Member]
Accounts payable	(24)	(82)
Accrued payroll	$ 0	0
Accrued interest		$ 0

Note 8 - Noncontrolling Inter_3

Note 8 - Noncontrolling Interest - Clyra Medical (Details Textual)			1 Months Ended		3 Months Ended
	Dec. 15, 2023	Jun. 30, 2020 USD ($) shares	Jul. 31, 2023 USD ($) shares	Jan. 31, 2023 shares	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares		Dec. 31, 2023 USD ($) shares	Apr. 08, 2022 USD ($)
Long-Term Line of Credit					$ 134,000			$ 134,000
Research and Development Expense					$ 784,000	$ 565,000
Preferred Stock, Shares Outstanding (in shares) \| shares					0			0
Common Stock, Shares, Issued (in shares) \| shares					295,801,370			292,945,747
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 0	225,000
Warrants and Rights Outstanding					$ 4,021,000	$ 122,000	[1]
Share Price (in dollars per share) \| $ / shares					$ 0.35
Clyra Medical [Member] \| Common Stock [Member]
Investment Owned, Balance, Shares (in shares) \| shares					5,322,775			5,322,775
Clyra Medical [Member] \| Preferred Stock, Series A [Member]
Investment Owned, Balance, Shares (in shares) \| shares					165,765			165,765
Clyra Medical [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	100
Stock Issued During Period, Shares, New Issues (in shares) \| shares					27,600	0
Shares Issued, Price Per Share (in dollars per share) \| $ / shares					$ 2.71
Research and Development Expense					$ 52,000
Stock Issued, Discount on Fair Value, Percentage					30%
Shares, Outstanding (in shares) \| shares					10,095,749
Common Stock, Shares, Outstanding (in shares) \| shares								10,000,749
Common Stock, Shares, Issued (in shares) \| shares					95,000
Preferred Stock Dividends and Other Adjustments					$ 327,000	$ 241,000
Clyra Medical [Member] \| Share-Based Payment Arrangement, Option [Member] \| Employees and Consultants [Member]
Share-Based Payment Arrangement, Expense					$ 59,000	$ 61,000
Share Price (in dollars per share) \| $ / shares					$ 4.5	$ 2.71
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount Rate					30%
Clyra Medical [Member] \| Warrants Expiring February 28, 2027 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) \| shares					47,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 7.5
Number of Accredited Investors					5
Proceeds from Issuance or Sale of Equity					$ 475,000
Clyra Medical [Member] \| Warrants Issued in Conjunction With the Sale of Series A Preferred Stock [Member]
Shares Issued, Price Per Share (in dollars per share) \| $ / shares					$ 3.72
Warrants and Rights Outstanding, Term (Year)					3 years
Warrants and Rights Outstanding					$ 524,000
Clyra Medical [Member] \| Clyra Unit Offering [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) \| shares					47,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) \| $ / shares					$ 7.5
Warrants and Rights Outstanding, Term (Year)					3 years
Warrants and Rights Outstanding					$ 57,000
Clyra Medical [Member] \| Preferred Shares Issued for Debt Owed to Biolargo [Member]
Debt Conversion, Converted Instrument, Amount			$ 96,000
Debt Conversion, Converted Instrument, Shares Issued (in shares) \| shares			30,833
Clyra Medical [Member] \| Preferred Class A [Member]
Stock Issued During Period, Shares, New Issues (in shares) \| shares					746,618
Preferred Stock, Shares Outstanding (in shares) \| shares					746,418
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 1,800,000
Clyra Medical [Member] \| Series A Preferred Stock [Member]
Shares Issued, Price Per Share (in dollars per share) \| $ / shares					$ 3.1
Preferred Stock, Shares Outstanding (in shares) \| shares								746,418
Preferred Stock, Dividend Rate, Percentage					15%
Preferred Stock, Convertible, Sale of Stock Amount					$ 5,000,000
Clyra Medical [Member] \| Revolving Credit Facility [Member] \| Vernal Bay Capital Group, LLC [Member] \| Inventory Line of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,000,000
Proceeds from Lines of Credit, Total		$ 260,000
Repayments of Lines of Credit					126,000
Stock Issued During Period, Shares, Commitment Fee (in shares) \| shares		32,200
Stock Issued During Period, Value, Commitment Fee		$ 70,000
Debt Instrument, Percentage of Principal Payment, Cap								15%
Clyra Medical [Member] \| Notes Payable, Other Payables [Member]
Debt Instrument, Face Amount									$ 100,000
Debt Instrument, Interest Rate, Stated Percentage									8%
Debt Instrument, Convertible, Sale of Stock Amount									$ 5,000,000
Debt Instrument, Convertible, Conversion Percentage									70%
Debt Instrument, Outstanding Balance					$ 100,000			$ 100,000
Vernal Bay Capital Group, LLC [Member] \| Conversion of Clyra Medical Stock Into Biolargo Common Stock [Member]
Stock Issued During Period, Shares, Commitment Fee (in shares) \| shares				32,200
Conversion of Stock, Shares Issued (in shares) \| shares				527,983

[1]Aggregate intrinsic value based on closing common stock price of $0.35 at March 31, 2024.

Note 8 - Noncontrolling Inter_4

Note 8 - Noncontrolling Interest - Clyra Medical - Common Shares Outstanding (Details) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Options outstanding, Granted (in shares)	0
Clyra Medical [Member]
Clyra options outstanding, balance (in shares)	1,478,922	1,583,329
Weighted average price, balance (in dollars per share)	$ 0.06	$ 0.06
Options outstanding, Granted (in shares)	25,833	42,582
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 4.05	$ 1.48
Weighted average remaining term, Outstanding (Year)	6 years 9 months 18 days	7 years 6 months
Clyra options outstanding, balance (in shares)	1,504,755
Weighted average price, balance (in dollars per share)	$ 0.38
Balance, Weighted Average Remaining Term (Year)	6 years 9 months 18 days	7 years 6 months
Unvested (in shares)	(12,300)
Weighted average price, Unvested (in dollars per share)	$ 2.71
Clyra options outstanding, balance (in shares)	1,492,455	1,625,911
Weighted average price, balance (in dollars per share)	$ 0.36	$ 0.09

Note 8 - Noncontrolling Inter_5

Note 8 - Noncontrolling Interest - Clyra Medical - Valuation Assumptions (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Clyra Medical [Member] \| Vendors and Employees [Member]
Risk free interest rate	3.48%		4.45%
Minimum [Member] \| Clyra Medical [Member] \| Vendors and Employees [Member]
Expected life in years (Year)	10 years
Maximum [Member] \| Clyra Medical [Member] \| Vendors and Employees [Member]
Expected volatility			49%
Expected life in years (Year)			10 years
Non Plan [Member]
Expected volatility	99%
Expected life in years (Year)	10 years
Non Plan [Member] \| Minimum [Member]
Risk free interest rate	0%
Non Plan [Member] \| Minimum [Member] \| Clyra Medical [Member] \| Vendors and Employees [Member]
Risk free interest rate	4.16%
Expected volatility	49%
Non Plan [Member] \| Maximum [Member]
Risk free interest rate		3.48%
Expected volatility		114%
Expected life in years (Year)		10 years

Note 8 - Noncontrolling Inter_6

Note 8 - Noncontrolling Interest - Clyra Medical - Warrants Outstanding (Details) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Warrants outstanding, balance (in shares)	51,590,300	49,023,398
Weighted average remaining life, balance (Year)	2 years	2 years 4 months 24 days
Warrants outstanding, balance (in shares)	53,802,444	51,850,412
Clyra Medical [Member]
Warrants outstanding, balance (in shares)	749,911	207,513
Granted Warrants, Balance (in shares)	47,500	72,581
Weighted average remaining life, balance (Year)	2 years 8 months 12 days	3 years 6 months
Warrants outstanding, balance (in shares)	797,411	280,094
Clyra Medical [Member] \| Minimum [Member]
Outstanding Warrants, Weighted Average Price Per Share (in dollars per share)	$ 3.74	$ 3.72
Granted Warrants, Weighted Average Price Per Share (in dollars per share)	7.5	3.72
Outstanding Warrants, Weighted Average Price Per Share (in dollars per share)	$ 3.96	$ 3.72

Note 8 - Noncontrolling Inter_7

Note 8 - Noncontrolling Interest - Clyra Medical - Summary of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounts payable	$ 1,663	$ 1,212
Accrued payroll	77	251
Accrued interest		25
Accounts payable and accrued expenses, total	1,740	1,488
Clyra Medical [Member]
Accounts payable	417	135
Accrued dividend	328	242
Accrued payroll	12	7
Accrued interest	15	13
Accounts payable and accrued expenses, total	$ 772	$ 397

Note 9 - BioLargo Engineering_2

Note 9 - BioLargo Engineering, Science and Technologies, LLC (Details Textual) - shares	1 Months Ended	3 Months Ended
	Sep. 30, 2017	Mar. 31, 2024	Dec. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)		0
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member]
Percentage of Profits Interests Vested		22.50%	22.50%
Seven Employees Working at BioLargo Engineering, Science & Technologies, LLC [Member] \| Non-Qualified Stock Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	1,750,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)	5 years
BioLargo Engineering, Science & Technologies, LLC [Member]
Subsidiary, Ownership Percentage, Parent	100%	82%

Note 10 - BioLargo Energy Tec_2

Note 10 - BioLargo Energy Technologies, Inc. (Details Textual)	3 Months Ended
	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 $ / shares shares
Share Price (in dollars per share) \| $ / shares	$ 0.35
BioLargo Energy Technologies, Inc (BETI) [Member]
Investment Owned, Balance, Shares (in shares)	9,050,000
Third Party [Member] \| Conversion Debt to Equity [Member]
Proceeds from Issuance or Sale of Equity \| $	$ 550,000
BioLargo Energy Technologies, Inc (BETI) [Member]
Investment Owned, Balance, Shares (in shares)	9,000,000
Stock Issued During Period, Shares, New Issues (in shares)	20,000	325,000
Share Price (in dollars per share) \| $ / shares	$ 2.5	$ 2
Number of Accredited Investors	1	6
Proceeds from Issuance or Sale of Equity \| $	$ 50,000
Shares, Outstanding (in shares)	9,467,000
BioLargo Energy Technologies, Inc (BETI) [Member] \| Conversion Debt to Equity [Member]
Conversion of Stock, Shares Issued (in shares)	25,000
BioLargo Energy Technologies, Inc (BETI) [Member] \| Biolargo [Member]
Proceeds from Issuance or Sale of Equity \| $	$ 100,000
Shares, Issued (in shares)	50,000
Biolargo [Member] \| Conversion Debt to Equity [Member]
Number of Accredited Investors	1
Conversion of Stock, Amount Converted \| $	$ 50,000

Note 11 - Business Segment In_3

Note 11 - Business Segment Information (Details Textual)	3 Months Ended
Note 11 - Business Segment Information (Details Textual)	Mar. 31, 2024
Number of Operating Segments	6

Note 11 - Business Segment In_4

Note 11 - Business Segment Information - Segment Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Revenue from Contract with Customer, Including Assessed Tax	$ 4,760,000	$ 3,742,000
Stock option expense	(488,000)	(256,000)
Depreciation	(36,000)	(22,000)
Research and Development Expense	(784,000)	(565,000)
BioLargo corporate	(763,000)	(477,000)
Interest income (expense)	(12,000)	(48,000)
Tangible assets	8,735,000		$ 7,094,000
Right of use, operating lease, net of amortization	1,068,000		1,092,000
Investment in South Korean joint venture	18,000		19,000
Total	9,821,000		8,205,000
Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	18,000		19,000
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Stock option expense	(429,000)	(195,000)
Depreciation	(10,000)	(6,000)
Research and Development Expense	(314,000)	(189,000)
BioLargo corporate	(1,244,000)	(799,000)
Interest income (expense)	(3,000)	(36,000)
Tangible assets	1,079,000		942,000
Right of use, operating lease, net of amortization	380,000		394,000
Total	1,477,000		1,355,000
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	18,000		19,000
Operating Segments [Member] \| Odor-No-More [Member]
Revenue from Contract with Customer, Including Assessed Tax	4,575,000	3,543,000
Depreciation	(5,000)	(4,000)
Research and Development Expense	0	0
BioLargo corporate	1,798,000	1,387,000
Interest income (expense)	(2,000)	(2,000)
Tangible assets	5,870,000		4,624,000
Right of use, operating lease, net of amortization	0		0
Total	5,870,000		4,624,000
Operating Segments [Member] \| Odor-No-More [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| BLEST [Member]
Tangible assets	734,000		1,083,000
Right of use, operating lease, net of amortization	688,000		698,000
Total	1,422,000		1,781,000
Operating Segments [Member] \| BLEST [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| Clyra Medical [Member]
Tangible assets	949,000		432,000
Right of use, operating lease, net of amortization	0		0
Total	949,000		432,000
Operating Segments [Member] \| Clyra Medical [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| BioLargo Energy Technologies, Inc (BETI) [Member]
Research and Development Expense	(80,000)	(32,000)
BioLargo corporate	(155,000)	(87,000)
Tangible assets	65,000		4,000
Right of use, operating lease, net of amortization	0		0
Total	65,000		4,000
Operating Segments [Member] \| BioLargo Energy Technologies, Inc (BETI) [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| BEST [Member]
BioLargo corporate	(66,000)	0
Tangible assets	0		0
Right of use, operating lease, net of amortization	0		0
Total	0		0
Operating Segments [Member] \| BEST [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| BioLargo Canada [Member]
Research and Development Expense	(80,000)	(135,000)
BioLargo corporate	(105,000)	(184,000)
Tangible assets	38,000		50,000
Right of use, operating lease, net of amortization	0		0
Total	38,000		50,000
Operating Segments [Member] \| BioLargo Canada [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	0		0
Operating Segments [Member] \| BioLargo Engineering, Science & Technologies, LLC [Member]
Revenue from Contract with Customer, Including Assessed Tax	356,000	363,000
Depreciation	(19,000)	(2,000)
Research and Development Expense	(352,000)	(245,000)
BioLargo corporate	(445,000)	(368,000)
Operating Segments [Member] \| Clyra Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	6,000
Stock option expense	(59,000)	(61,000)
Depreciation	(2,000)	(10,000)
Research and Development Expense	(121,000)	(134,000)
BioLargo corporate	(546,000)	(426,000)
Interest income (expense)	(7,000)	(10,000)
Consolidation, Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax	(171,000)	(170,000)
Research and Development Expense	163,000	$ 170,000
Tangible assets	0		(41,000)
Right of use, operating lease, net of amortization	0		0
Total	0		(41,000)
Consolidation, Eliminations [Member] \| Investment in South Korean Joint Venture [Member]
Investment in South Korean joint venture	$ 0		$ 0

Note 12 - Leases (Details Textu

Note 12 - Leases (Details Textual) - USD ($)	3 Months Ended		12 Months Ended
Note 12 - Leases (Details Textual) - USD ($)	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Operating Lease, Expense	$ 88,000	$ 83,000
Lessee, Operating Lease, Renewal Term (Year)	4 years
Increase (Decrease) in Operating Lease, Right-of-use Assets			$ 394,000
Lessee, Operating Lease, Discount Rate	18%
Operating Lease, Weighted Average Remaining Lease Term (Year)	7 years		7 years
Lessee, Operating Lease, Liability, to be Paid			$ 2,042,000

Note 12 - Leases - Schedule of

Note 12 - Leases - Schedule of Future Minimum Lease Payments (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
December 31, 2024		$ 276,000
December 31, 2025		282,000
December 31, 2026		289,000
December 31, 2027		296,000
December 31, 2028		245,000
Thereafter		654,000
Total minimum lease payments		2,042,000
Less imputed interest		(933,000)
Total operating lease liability	$ 1,090,000	1,109,000
BioLargo/ONM Lease [Member]
December 31, 2024		122,000
December 31, 2025		125,000
December 31, 2026		129,000
December 31, 2027		133,000
December 31, 2028		79,000
Total minimum lease payments		588,000
BLEST Lease [Member]
December 31, 2024		154,000
December 31, 2025		157,000
December 31, 2026		160,000
December 31, 2027		163,000
December 31, 2028		166,000
Thereafter		654,000
Total minimum lease payments		$ 1,454,000

Note 13 - Subsequent Events (De

Note 13 - Subsequent Events (Details Textual)		1 Months Ended
Note 13 - Subsequent Events (Details Textual)	Apr. 01, 2024 shares	May 13, 2024 USD ($) shares	Mar. 31, 2024 shares	Dec. 31, 2023 shares
Common Stock, Shares, Issued (in shares)			295,801,370	292,945,747
Subsequent Event [Member] \| 2024 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		10,000
Subsequent Event [Member] \| Share-Based Payment Arrangement, Option [Member]
Stock Issued During Period, Shares, New Issues (in shares)		194,818
Subsequent Event [Member] \| Issuance to Two Accredited Investors [Member]
Common Stock, Shares, Issued (in shares)		454,547
Proceeds from Issuance or Sale of Equity \| $		$ 150,000
Number of Accredited Investors		2
Subsequent Event [Member] \| BETI Common Stock [Member] \| Conversion of BETI Common Stock to BioLargo Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)	20,000
Conversion of Stock, Shares Issued (in shares)	378,788