Duolingo (DUOL) 10-Q8 Aug 232023 Q2 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	6 Months Ended
Cover Page - shares	Jun. 30, 2023	Aug. 07, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-40653
Entity Registrant Name	Duolingo, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-3055872
Entity Address, Address Line One	5900 Penn Avenue
Entity Address, City or Town	Pittsburgh
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15206
City Area Code	(412)
Local Phone Number	567-6602
Title of 12(b) Security	Class A common stock, $0.0001 per share
Trading Symbol	DUOL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001562088
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		35,374,823
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		6,162,615

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 678,665	$ 608,180
Accounts receivable	53,406	46,728
Deferred cost of revenues	42,720	35,041
Income tax receivable	2,363	0
Prepaid expenses and other current assets	7,787	7,234
Total current assets	784,941	697,183
Assets, Noncurrent
Property and equipment, net	12,571	12,969
Goodwill	4,050	4,050
Intangible assets, net	10,396	8,497
Operating lease right-of-use assets	20,976	22,508
Deferred tax assets	633	633
Other assets	1,236	1,507
Total assets	834,803	747,347
Current liabilities
Accounts payable	2,305	1,177
Deferred revenues	192,753	157,550
Income tax payable	62	1,069
Accrued expenses and other current liabilities	21,986	21,970
Total current liabilities	217,106	181,766
Liabilities, Noncurrent
Long-term obligation under operating leases	21,292	23,503
Total liabilities	238,398	205,269
Commitments and contingencies (Note 8)
Stockholders’ equity
Class A common stock, $0.0001 par value; 2,000,000 shares authorized as of June 30, 2023 and December 31, 2022; 35,368 and 31,899 issued and outstanding at June 30, 2023 and December 31, 2022, respectively Class B common stock, $0.0001 par value; 30,000 shares authorized as of June 30, 2023 and December 31, 2022; 6,163 and 8,462 issued and outstanding at June 30, 2023 and December 31, 2022, respectively	4	4
Additional paid-in capital	825,746	772,562
Accumulated deficit	(229,345)	(230,488)
Total stockholders’ equity	596,405	542,078
Total liabilities and stockholders' equity	$ 834,803	$ 747,347

UNAUDITED CONDENSED CONSOLIDA_2

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Common Class A
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	35,368,000	31,899,000
Common stock, shares outstanding (in shares)	35,368,000	31,899,000
Common Class B
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, shares issued (in shares)	6,163,000	8,462,000
Common stock, shares outstanding (in shares)	6,163,000	8,462,000

UNAUDITED CONDENSED CONSOLIDA_3

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
Revenues	$ 126,839	$ 88,386	$ 242,500	$ 169,606
Cost of revenues	33,788	23,869	65,280	45,359
Gross profit	93,051	64,517	177,220	124,247
Operating expenses:
Research and development	47,947	34,217	93,791	63,998
Sales and marketing	17,734	15,277	34,335	30,217
General and administrative	32,235	30,057	62,478	56,913
Total operating expenses	97,916	79,551	190,604	151,128
Loss from operations	(4,865)	(15,034)	(13,384)	(26,881)
Other expense, net of other income	(268)	(539)	(86)	(851)
Loss before interest income and income taxes	(5,133)	(15,573)	(13,470)	(27,732)
Interest income	7,543	669	13,182	702
Income (loss) before income taxes	2,410	(14,904)	(288)	(27,030)
(Benefit) provision for income taxes	(1,315)	141	(1,431)	169
Net income (loss)	3,725	(15,045)	1,143	(27,199)
Net comprehensive income (loss)	$ 3,725	$ (15,045)	$ 1,143	$ (27,199)
Net income (loss) per share attributable to Class A and Class B common stockholders, basic (in usd per share)	$ 0.09	$ (0.38)	$ 0.03	$ (0.70)
Net income (loss) per share attributable to Class A and Class B common stockholders, diluted (in usd per share)	$ 0.08	$ (0.38)	$ 0.02	$ (0.70)

UNAUDITED CONDENSED CONSOLIDA_4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021		38,272
Beginning balance at Dec. 31, 2021	$ 513,056	$ 4	$ 683,966	$ (170,914)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation expense	32,700		32,700
Stock options exercised (in shares)		1,206
Stock options exercised	$ 9,662		9,662
Release of restricted stock units (in shares)	109
Release of restricted stock units	$ 0
Net income (loss)	(27,199)			(27,199)
Ending balance (in shares) at Jun. 30, 2022		39,587
Ending balance at Jun. 30, 2022	528,219	$ 4	726,328	(198,113)
Beginning balance (in shares) at Mar. 31, 2022		39,077
Beginning balance at Mar. 31, 2022	520,714	$ 4	703,778	(183,068)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation expense	18,114		18,114
Stock options exercised (in shares)		450
Stock options exercised	4,436		4,436
Release of restricted stock units (in shares)		60
Release of restricted stock units	0
Net income (loss)	(15,045)			(15,045)
Ending balance (in shares) at Jun. 30, 2022		39,587
Ending balance at Jun. 30, 2022	528,219	$ 4	726,328	(198,113)
Beginning balance (in shares) at Dec. 31, 2022		40,361
Beginning balance at Dec. 31, 2022	542,078	$ 4	772,562	(230,488)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation expense	$ 44,787		44,787
Stock options exercised (in shares)	916	916
Stock options exercised	$ 8,397		8,397
Release of restricted stock units (in shares)		254
Release of restricted stock units	0
Net income (loss)	1,143			1,143
Ending balance (in shares) at Jun. 30, 2023		41,531
Ending balance at Jun. 30, 2023	596,405	$ 4	825,746	(229,345)
Beginning balance (in shares) at Mar. 31, 2023		41,018
Beginning balance at Mar. 31, 2023	565,188	$ 4	798,254	(233,070)
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Stock-based compensation expense	23,714		23,714
Stock options exercised (in shares)		374
Stock options exercised	3,778		3,778
Release of restricted stock units (in shares)		139
Release of restricted stock units	0
Net income (loss)	3,725			3,725
Ending balance (in shares) at Jun. 30, 2023		41,531
Ending balance at Jun. 30, 2023	$ 596,405	$ 4	$ 825,746	$ (229,345)

UNAUDITED CONDENSED CONSOLIDA_5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net income (loss)	$ 1,143	$ (27,199)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	3,396	1,944
Stock-based compensation expense	44,787	32,700
Gain on sale of capitalized software	(100)	0
Changes in assets and liabilities:
Deferred revenue	35,203	29,927
Accounts receivable	(6,678)	4,954
Deferred cost of revenues	(7,679)	(4,999)
Prepaid expenses and other current assets	(2,916)	(738)
Accounts payable	1,059	(6,314)
Accrued expenses and other current liabilities	(1,036)	3,505
Noncurrent assets and liabilities	(408)	(491)
Net cash provided by operating activities	66,771	33,289
Cash flows from investing activities:
Capitalized software expense and purchases of intangible assets	(3,275)	(2,522)
Purchase of property and equipment	(1,508)	(3,191)
Proceeds from sale of capitalized software	100	0
Net cash used for investing activities	(4,683)	(5,713)
Cash flows from financing activities:
Proceeds from exercise of stock options	8,397	9,662
Net cash provided by financing activities	8,397	9,662
Net increase in cash and cash equivalents	70,485	37,238
Cash and cash equivalents - Beginning of period	608,180	553,922
Cash and cash equivalents - End of period	678,665	591,160
Supplemental disclosure of cash flow information:
Cash paid for interest	0	0
Cash paid for income taxes	1,939	608
Supplemental disclosure of noncash operating activities:
Implementation costs for cloud computing included in Current liabilities	0	7
Supplemental disclosure of noncash investing activities:
Capitalized software and purchases of intangible assets included in Current liabilities	0	12
Property and equipment included in Current liabilities	114	1,058
Landlord incentive included in Prepaid expenses and other current assets	$ 0	$ 2,148

DESCRIPTION OF THE BUSINESS AND

DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	6 Months Ended
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION Duolingo, Inc. (the “Company” or “Duolingo”) was formed on August 18, 2011, and the Duolingo app was launched to the general public on June 19, 2012. The Company’s headquarters are located in Pittsburgh, Pennsylvania. Duolingo is a US-based mobile learning platform, as well as a digital language proficiency assessment exam. The Company has a freemium business model: the app and the website are accessible free of charge, although Duolingo also offers premium services for a subscription fee. As of the date of this filing, Duolingo offers courses in over 40 different languages, including Spanish, English, French, German, Italian, Portuguese, Japanese and Chinese. We have locations in the United States, China and Germany. Principles of Consolidation —The Unaudited Condensed Consolidated Financial Statements include the accounts of the Company and subsidiaries over which the Company has control. All intercompany transactions and balances have been eliminated. Basis of Presentation —The accompanying Unaudited Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) from the Company’s accounting records and reflect the consolidated financial position and results of operations for the three and six months ended June 30, 2023 and 2022. Unless otherwise specified, all dollar amounts (other than per share amounts) are referred to in thousands. The Unaudited Condensed Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such SEC rules. We believe that the disclosures made are adequate to make the information presented not misleading. In our opinion, all adjustments considered necessary for a fair presentation of the financial statements have been included, and all adjustments are of a normal and recurring nature. We consistently applied the accounting policies consistent with the annual Unaudited Condensed Consolidated Financial Statements elsewhere in this Quarterly Report on Form 10-Q, in preparing these Unaudited Condensed Consolidated Financial Statements. These Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited financial statements and the notes for the fiscal year ended December 31, 2022 included in the Annual Report on Form 10-K and filed with the SEC.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Jun. 30, 2023
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Accounting Principles —The Unaudited Condensed Consolidated Financial Statements and accompanying notes are prepared in accordance with GAAP. Use of Estimates— The preparation of Unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Unaudited Condensed Consolidated Financial Statements and accompanying notes. Significant estimates and assumptions reflected in the Unaudited Condensed Consolidated Financial Statements include, but are not limited to, useful lives of property and equipment, valuation of deferred tax assets and liabilities, stock-based compensation, common stock valuation, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives and contingent liabilities. Actual results may differ materially from such estimates. Management believes that the estimates, and judgments upon which they rely, are reasonable based upon information available to them at the time that these estimates and judgments are made. To the extent that there are material differences between these estimates and actual results, the Company’s Unaudited Condensed Consolidated Financial Statements will be affected. Cash and Cash Equivalents— Cash consists primarily of cash on hand and bank deposits. Cash equivalents consist primarily of money market accounts with maturities of three months or less at the date of acquisition and are stated at cost, which approximates fair value. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times. The following table shows the breakout between cash and money market funds. (In thousands) June 30, December 31, Cash $ 23,541 $ 91,189 Money market funds 655,124 516,991 Total $ 678,665 $ 608,180 The Money market funds are considered Level 1 financial assets. Level 1 financial assets use inputs that are the unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. Advertising Costs — Advertising costs were approximately $12,206 and $23,299 for the three and six months ended June 30, 2023, respectively, and $10,593 and $21,547 for the three and six months ended June 30, 2022, respectively, and are included within Sales and marketing in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). Income Taxes— The Company’s provision for income taxes is computed by using an estimate of the annual effective tax rate, adjusted for discrete items taken into account in the relevant period, if any. Each quarter, the annual effective income tax rate is recomputed and if there are material changes in the estimate, a cumulative adjustment is made. Concentration of Credit Risk —The Company’s concentration of credit risk relates to financial institutions holding the Company’s cash and cash equivalents and platforms with significant accounts receivable balances and revenue transactions. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times. Management believes that the financial institutions that hold the Company’s deposits are financially credit worthy and, accordingly, minimal credit risk exists with respect to those balances. The majority of our revenue comes through our subscriptions and advertising streams and payments are made to Duolingo through service providers. The top two service providers, Apple and Google, accounted for 68.0% and 18.4% of total Accounts receivable as of June 30, 2023, respectively. The top two service providers, Apple and Google, accounted for 56.2% and 27.5% of total Accounts receivable as of December 31, 2022, respectively. Three service providers, Apple, Google and Stripe, processed 58.2%, 26.1%, and 11.9%, and 57.7%, 26.2% and 11.9% of total Revenues for the three and six months ended June 30, 2023, respectively. Two services providers, Apple and Google, processed 53.5% and 28.4%, and 52.3% and 28.8% of total Revenues for the three and six months ended June 30, 2022, respectively. Impairment of long-lived assets— The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset. No assets were impaired during the three and six months ended June 30, 2023 and 2022. Recently Issued Pronouncements Not Yet Adopted There are no recently issued accounting pronouncements that the Company has not yet adopted that they believe are applicable or would have a material impact on the financial statements of the Company. Recently Adopted Accounting Pronouncements There are no recently adopted accounting pronouncements.

REVENUE

REVENUE	6 Months Ended
REVENUE	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE The Company has three predominant sources of revenues; time-based subscriptions, in-app advertising placement by third parties, and the Duolingo English Test. Revenue is recognized upon transfer of control of promised products or services to users in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company does not enter into contracts with a customer that contain multiple promises that result in multiple performance obligations. Revenue is recorded net of taxes assessed by a government authority that are both imposed on and concurrent with specific revenue transactions between us and our users. Revenue from time-based subscriptions includes a stand-ready obligation to provide hosting services that are consumed by the customer over the subscription period. Users can purchase Duolingo monthly or they can purchase a six-month or year-long subscription and pay for the subscription at the time of purchase. Under the year-long subscription, users can also purchase a single plan or a family plan. The family plan includes up to six users on one subscription. Such payments are initially recorded to deferred revenue. The user has the ability to download limited content offline. However, as there is a significant level of integration and interdependency with the online functionality, the Company considers the service to be a single performance obligation for the online and offline content. The Company enters into arrangements with advertising networks to monetize the in-app advertising inventory. Revenue from in-app advertising placement is recognized at a point in time when the advertisement is placed and is based upon the amount received. Duolingo English Test revenue is generally recognized once the tests have gone through the proctoring process and a certification decision has been made. This process usually takes less than 48 hours after the test has been completed and uploaded. Customers have 21 days from the date of purchase to take the exam or their purchase will expire and revenue will be recognized. Virtually all customers complete their exams prior to expiration. Sometimes organizations may purchase tests in bulk via coupons with a one year expiration date. The Company will defer revenue from all tests that have neither been proctored nor expired. The Company’s users have the option to purchase consumable in-app virtual goods. The Company recognizes revenue over the period in which the user consumes the virtual good, which is generally within a month. The Company also recognizes revenue from Duo’s Taquería , a restaurant that opened during 2022, in the space adjacent to our headquarters in Pittsburgh. Revenue from Duo’s Taquería is recognized at a point in time when the sales are made. Principal Agent Considerations —The Company makes its application available to be downloaded through third-party digital distribution service providers. Users who purchase subscriptions also pay through the respective app stores. The Company evaluates the purchases via third-party payment processors to determine whether its revenues should be reported gross or net of fees retained by the payment processor. The Company is the principal in the transaction with the end user as a result of controlling, hosting, and integrating the delivery of the virtual items to the end user. The Company records revenue gross as a principal and records fees paid to third-party payment processors as Cost of revenues. Contract Balances —Deferred revenue mostly consists of payments we receive in advance of revenue recognition, and is mostly related to time-based subscriptions, which will be recognized into revenue over the course of the upcoming year (recognized over 12 months or less). Additionally, the Duolingo English Test has deferred revenue related to tests that have been purchased, but will not be recognized until the tests have been proctored. Disaggregation of Revenue In accordance with ASC 606, Revenue from Contracts with Customers , the Company disaggregates revenue from contracts with customers into revenue stream, which most closely depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Revenues: Subscription $ 95,158 $ 65,194 $ 181,343 $ 123,204 Advertising 13,061 11,218 24,696 22,966 Duolingo English Test 9,809 8,036 19,781 16,116 Other (1) 8,811 3,938 16,680 7,320 Total revenues $ 126,839 $ 88,386 $ 242,500 $ 169,606 ________________ (1) Other revenue is mainly comprised of in-app purchases of virtual goods. Changes in deferred revenues were as follows: Six Months Ended June 30, (In thousands) 2023 2022 Beginning balance—January 1 $ 157,550 $ 98,267 Amount from beginning balance recognized into revenue (112,514) (69,597) Recognition of deferred revenue (88,507) (63,821) Deferral of revenue 236,224 163,345 Ending balance—June 30 $ 192,753 $ 128,194

PROPERTY and EQUIPMENT, net

PROPERTY and EQUIPMENT, net	6 Months Ended
PROPERTY and EQUIPMENT, net	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
PROPERTY and EQUIPMENT, net	PROPERTY and EQUIPMENT, net Property and equipment consists of the following as of June 30, 2023 and December 31, 2022: (In thousands) June 30, December 31, 2022 Leasehold improvements $ 17,134 $ 15,983 Furniture, fixtures and equipment 5,675 5,204 Total property and equipment 22,809 21,187 Less: accumulated depreciation (10,238) (8,218) Total property and equipment, net $ 12,571 $ 12,969 Depreciation expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Research and development $ 409 $ 463 $ 816 $ 597 Sales and marketing 45 59 93 78 General and administrative 557 166 1,111 578 Total $ 1,011 $ 688 $ 2,020 $ 1,253

INTANGIBLE ASSETS AND GOODWILL

INTANGIBLE ASSETS AND GOODWILL	6 Months Ended
INTANGIBLE ASSETS AND GOODWILL	Jun. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND GOODWILL	INTANGIBLE ASSETS AND GOODWILL Intangible assets consist mostly of capitalized software, with $117 and $18 of other intangible assets as of June 30, 2023 and December 31, 2022, respectively. (In thousands) June 30, December 31, 2022 Intangible assets $ 19,794 $ 16,827 Less: accumulated amortization (9,398) (8,330) Intangible assets, net $ 10,396 $ 8,497 The Company capitalized $3,176 and $2,534 of software development costs during the six months ended June 30, 2023 and 2022, respectively. Amortization expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Cost of revenues $ 402 $ 273 $ 805 $ 273 Sales and marketing 221 209 571 418 Total $ 623 $ 482 $ 1,376 $ 691

INCOME TAXES

INCOME TAXES	6 Months Ended
INCOME TAXES	Jun. 30, 2023
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXESYear-to-date income tax expense or benefit is the product of the most current projected annual effective tax rate (“PAETR”) and the actual year-to-date pretax income (loss) adjusted for any discrete items. The income tax expense or benefit for a particular quarter, is the difference between the year-to-date calculation of income tax expense or benefit and the year-to-date calculation for the prior quarter. Items unrelated to current period ordinary income or (loss) are recognized entirely in the period identified as a discrete item of tax. The Company’s PAETR differs from the US federal statutory rate of 21.0% during the three and six months ended June 30, 2023 and 2022 primarily due to the impact of maintaining a US valuation allowance provided on US deferred tax assets. The Company continues to maintain a full valuation allowance on US federal and state net deferred tax assets for the period ending June 30, 2023 as a result of pre-tax losses incurred since the Company’s inception in early 2012. The Company is projecting pre-tax loss in 2023. The Company’s income before taxes, income tax provision or benefit and effective tax rates were as follows: Three Months Ended June 30, Six Months Ended June 30, (In thousands, except percentages) 2023 2022 2023 2022 Income (loss) before income taxes $ 2,410 $ (14,904) $ (288) $ (27,030) (Benefit) provision for income taxes (1,315) 141 $ (1,431) $ 169 Effective tax rate (54.6) % (0.9) % 496.9 % (0.6) %

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	6 Months Ended
STOCK-BASED COMPENSATION	Jun. 30, 2023
Equity [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Prior to the IPO, the Company granted options to purchase shares of the Company’s common stock and restricted stock units (“RSU”) in respect of shares of the Company’s common stock to employees, directors and consultants under the Company’s 2011 Equity Incentive Plan. In July 2021, Duolingo adopted the 2021 Incentive Award Plan (“2021 Plan”) and the 2021 Employee Stock Purchase Plan (“ESPP”), each of which became effective on July 26, 2021 in connection with the IPO. An aggregate of 7,946 shares and 1,119 shares of Class A common stock were made available for future issuance under the 2021 Plan and ESPP, respectively. On each January 1, the number of shares of the Company’s Class A common stock available for issuance under the 2021 Plan have been, and through January 1, 2031, will be, increased by the lesser of (i) 5% of the shares outstanding on the preceding December 31 (calculated on an as-converted basis) and (B) such smaller number of shares of common stock as determined by the Board or the Committee (as defined in the 2021 Plan). On January 1, 2023, the shares available under the 2021 Plan and ESPP were increased by 2,018 shares and 319 shares, respectively. The Company’s stock options vest based on terms in the stock option agreements, which generally provide for vesting over four years based on continued service to the Company and its subsidiaries. Each option has a term of ten years. Stock options granted under the 2021 Plan must generally have an exercise price of not less than the estimated fair market value of the underlying Class A common stock at the date of the grant. No options have been granted under the 2021 Plan. A summary of stock option activity under the Plans was as follows: (In thousands, except prices and years) Number of Weighted- Weighted- average remaining contractual life (years) Aggregate intrinsic value Options outstanding at January 1, 2023 4,410 $ 14.04 6.25 $ 251,832 Granted (1) — Exercised (916) 9.23 Forfeited and expired (26) 13.63 Options outstanding at June 30, 2023 3,468 $ 15.31 6.03 $ 443,657 Options exercisable at June 30, 2023 3,076 $ 14.63 5.90 $ 394,674 ________________ (1) There were no stock options granted during the six months ended June 30, 2023. The total intrinsic value of options exercised was approximately $106,750 and $95,677 for the periods ended June 30, 2023 and 2022, respectively. A summary of RSU activity under the Plans was as follows: (In thousands, except prices) Restricted stock units Weighted- Outstanding at January 1, 2023 2,036 $ 85.74 Granted 708 131.32 Released (254) 84.91 Forfeited (117) 93.00 Outstanding at June 30, 2023 2,373 $ 99.07 As of June 30, 2023, there was approximately $3,308 of unrecognized compensation cost related to stock options granted under the plans with a weighted-average period of approximately one year. The amount of unrecognized compensation expense for RSUs as of June 30, 2023 was $217,528 with a weighted-average period of approximately three years. Total unrecognized compensation expense as of June 30, 2023 was $220,836. There were 9,570 shares available for grant at June 30, 2023. Performance-based RSUs In June 2021, the Company granted an aggregate of 1,800 performance-based RSUs (the “Founder Awards”) to the Company’s founders. The Founder Awards vest upon the satisfaction of both a service-based condition and a performance-based condition and generally are settled one year after vesting. The service-based condition is satisfied as to 25% of the Founder Awards on each anniversary of the completion of the IPO on July 27, 2021, subject to the continuous service of the founders through the applicable date. The performance-based condition will be satisfied with respect to each of 10 equal tranches only if the trailing 60-calendar day volume-weighted-average closing trading price of the Company’s Class A common stock reaches certain stock-price hurdles for each such tranche, as set forth below, over a period of 10 years from the date of grant. Any RSUs associated with stock-prices hurdle not achieved by the tenth anniversary of the date of grant will terminate and be canceled for no additional consideration to the founders. The stock-price hurdles and number of RSUs eligible to vest will be adjusted to reflect any stock splits, stock dividends, combinations, reorganizations, reclassifications, or similar events under the 2021 Plan. The Founder Awards will be settled in shares of the Company’s Class B common stock. Tranche Company Stock Price Hurdle Number of RSUs Eligible to Vest 1 $ 127.50 90 2 $ 153.00 90 3 $ 178.50 90 4 $ 204.00 180 5 $ 255.00 180 6 $ 306.00 180 7 $ 357.00 180 8 $ 408.00 180 9 $ 612.00 270 10 $ 816.00 360 The Company estimated the grant date fair value of the Founder Awards using a model based on multiple stock-price paths developed through the use of a Monte Carlo simulation that incorporates into the valuation the possibility that the stock-price hurdles may not be satisfied. The weighted-average grant date fair value of the Founder Awards was estimated to be $61.56 per share and the Company estimates that it will recognize total stock-based compensation expense of approximately $110,817 over the derived service period of each of the ten separate tranches which is between 3.58 – 5.92 years. If the stock-price hurdles are met sooner than the requisite service period, the stock-based compensation expense will be adjusted to prospectively recognize the remaining expense over the remaining derived service period. Provided that the founders continue to provide services to the Company, stock-based compensation expense is recognized over the derived service period, regardless of whether the stock-price hurdles are achieved. The stock-price hurdles for the first two tranches were met during 2021. With respect to these two tranches in combination, the service-based condition has been satisfied. As of the date of this Quarterly Report on Form 10-Q, no additional stock-price hurdles have been met. The Company recognized $7,094 and $14,234 of stock-based compensation expense related to these awards for the three and six months ended June 30, 2023, respectively, and $8,108 and $16,127 for the three and six months ended June 30, 2022, respectively, which is included within General and administrative in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). As of June 30, 2023, there is $49,123 of unrecognized compensation expense related to these awards. Total stock-based compensation expense was $23,714 and $44,787 for the three and six months ended June 30, 2023, respectively, and $18,114 and $32,700 for the three and six months ended June 30, 2022, respectively. Stock based compensation expense is included in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) as shown in the following table: Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Cost of revenues $ 14 $ 10 $ 25 $ 16 Research and development 10,978 5,773 20,324 9,405 Sales and marketing 969 595 1,748 943 General and administrative 11,753 11,736 22,690 22,336 Total $ 23,714 $ 18,114 $ 44,787 $ 32,700 Nominal amounts of stock based compensation expense is capitalized into intangible assets for the three and six months ended June 30, 2023 and 2022.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
COMMITMENTS AND CONTINGENCIES	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Proceedings — From time to time, the Company may become involved in various legal proceedings in the ordinary course of its business and may be subject to third-party infringement claims. The outcome of any such claims or proceedings, regardless of the merits, is inherently uncertain. The Company is not currently party to any material legal proceedings. Related Parties — The Company has determined that there were no transactions with related parties as of or during the three and six months ended June 30, 2023 and 2022.

ACCRUED EXPENSES AND OTHER CURR

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	6 Months Ended
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	Jun. 30, 2023
Other Liabilities Disclosure [Abstract]
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accrued expenses and other current liabilities consisted of the following: (In thousands) June 30, December 31, 2022 Obligations under current leases $ 6,053 $ 4,903 Marketing related accruals 3,993 3,464 Employee-related costs 2,726 4,233 Sales and VAT tax accrual 2,476 2,396 Other 6,738 6,974 Total $ 21,986 $ 21,970

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN	6 Months Ended
EMPLOYEE BENEFIT PLAN	Jun. 30, 2023
Postemployment Benefits [Abstract]
EMPLOYEE BENEFIT PLAN	EMPLOYEE BENEFIT PLANThe Company sponsors a profit sharing plan with a 401(k) feature, the Duolingo Retirement Plan (the “Plan”), for eligible employees. The current Plan, effective January 1, 2021, provides for Company safe harbor matching contributions of 100% of the first 4% of the employees’ elective deferrals and 50% of the next 2%, with vesting starting upon the first day of employment. The Company also has the option to make discretionary matching or profit sharing contributions. The Company made safe harbor matching contributions of approximately $1,473 and $2,870 for the three and six months ended June 30, 2023, respectively, and $1,059 and $2,042 for the three and six months ended June 30, 2022, respectively. The Company did not make any discretionary matching or profit sharing contributions during the three and six months ended June 30, 2023 and 2022.

EARNINGS (LOSS) PER SHARE

EARNINGS (LOSS) PER SHARE	6 Months Ended
EARNINGS (LOSS) PER SHARE	Jun. 30, 2023
Earnings Per Share [Abstract]
EARNINGS (LOSS) PER SHARE	EARNINGS (LOSS) PER SHARE Basic and diluted net income (loss) per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. The diluted net income per share attributable to common stockholders is calculated by giving effect to all potential dilutive common stock equivalents outstanding for the period. The rights, including the liquidation and dividend rights, of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 20 votes per share. Each share of Class B common stock is convertible into a share of Class A common stock voluntarily at any time by the holder, and automatically upon certain events. The Class A common stock has no conversion rights. As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportional basis and the resulting net income (loss) per share attributable to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. Three Months Ended June 30, Six Months Ended June 30, (In thousands, except per share data) 2023 2022 2023 2022 Numerator: Net income (loss) attributable to Class A and Class B common stockholders $ 3,725 $ (15,045) $ 1,143 $ (27,199) Denominator: Weighted-average shares in computing net income (loss) per share attributable to Class A and Class B common stockholders, basic and diluted 41,222 39,274 40,921 38,934 Effect of dilutive securities Founder awards where performance has been met 180 — 180 — Dilutive effect of stock options outstanding (1) 3,097 — 3,097 — RSUs outstanding 2,373 — 2,373 — Denominator for dilutive net income per common share - weighted-average shares 46,872 39,274 46,571 38,934 Basic income (loss) per common share $ 0.09 $ (0.38) $ 0.03 $ (0.70) Diluted income (loss) per common share $ 0.08 $ (0.38) $ 0.02 $ (0.70) ________________ (1) The Company had 3.5 million options outstanding as of June 30, 2023. The estimated dilutive effect is calculated as the number of shares expected to be issued upon vesting or exercise, adjusted for the strike price proceeds that are received by the Company and assumed to be used to repurchase shares of Duolingo common stock. Since the Company was in a net loss position for the three and six months ended June 30, 2022 there is no difference between the number of shares used to calculate basic and diluted loss per share. The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows: (In thousands) June 30, 2022 Founder awards where performance has been met 180 Stock options outstanding (1) 4,967 RSUs outstanding (1) 1,822 Total 6,969 ________________ (1) Prior year amounts were adjusted in the current year table to include unvested options and RSUs. Founder awards of 1,620, where the performance criteria has not been satisfied, are excluded from the above table because the stock-price hurdles for those awards had not been met as of June 30, 2023.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
SUBSEQUENT EVENTS	Jun. 30, 2023
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTSNone.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pay vs Performance Disclosure
Net income (loss) attributable to Class A and Class B common stockholders	$ 3,725	$ (15,045)	$ 1,143	$ (27,199)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	6 Months Ended
Insider Trading Arrangements	Jun. 30, 2023 shares	Jun. 30, 2023 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Terminated	false
Stephen Chen [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On June 2, 2023, Stephen Chen, General Counsel, entered into a 10b5-1 sales plan (the “Chen 10b5-1 Sales Plan”) intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act which provides for the potential exercise of vested stock options and the associated sale of up to 14,167 shares of the Company’s Class A common stock. The Chen 10b5-1 Sales Plan will remain in effect until the earlier of (1) May 31, 2024, (2) the date on which an aggregate of 14,167 shares of the Company’s common stock have been sold under the Chen 10b5-1 Sales Plan, or (3) such time as the Chen 10b5-1 Sales Plan is otherwise terminated according to its terms.
Name	Stephen Chen
Title	General Counsel
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	June 2, 2023
Rule 10b5-1 Arrangement Terminated	false
Arrangement Duration	364 days
Aggregate Available	14,167	14,167
Severin Hacker [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On June 2, 2023, the SBH Trust dated March 10, 2020 (the “SBH Trust”) and the Hacker Charitable Trust, of which Dr. Severin Hacker, Chief Technology Officer and director, is the Trustee, entered into a joint 10b5-1 sales plan (the “Hacker 10b5-1 Sales Plan”) intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act, pursuant to which a maximum aggregate of 190,000 shares of the Company’s Class A common stock may be sold (up to 120,000 shares by the SBH Trust and up to 70,000 by the Hacker Charitable Trust). The Hacker 10b5-1 Sales Plan will remain in effect until the earlier of (1) September 30, 2024, (2) upon the completed sale of an aggregate of 190,000 shares of the Company’s Class A common stock have been sold under the Hacker 10b5-1 Sales Plan, or (3) such time as the Hacker 10b5-1 Sales Plan is otherwise terminated according to its terms.
Name	Severin Hacker
Title	Chief Technology Officer and director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	June 2, 2023
Rule 10b5-1 Arrangement Terminated	false
Arrangement Duration	486 days
Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On June 9, 2023, Matthew Skaruppa, Chief Financial Officer, modified an existing trading plan intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act, originally adopted on September 8, 2022 (the “Original Skaruppa 10b5-1 Sales Plan”), to modify the amount of shares, price limits and timing of sales under the plan. The Original Skaruppa 10b5-1 Sales Plan provided for (i) the potential exercise of vested stock options and the associated sale of up to 76,000 shares of the Company’s Class A common stock and (ii) the sale of the net number of shares of Class A common stock underlying 17,315 restricted stock units received after giving effect to the number of shares sold to satisfy tax withholding obligations on each vesting date specified under the Original Skaruppa 10b5-1 Sales Plan (such total number of shares covered under clause (ii) is not determinable). Prior to its termination, 41,764 shares of Class A common Stock were sold pursuant to the Original Skaruppa 10b5-1 Sales Plan, and an aggregate of 44,000 shares of Class A underlying vested stock options remained unsold and 7,551 restricted stock units remained unvested. The modified trading arrangement (the “Skaruppa 10b5-1 Sales Plan”) is intended to satisfy the affirmative defense of Rule 10b5-1(c) of the Exchange Act and provides for (i) the potential exercise of vested stock options and the associated sale of up to 100,000 shares of the Company’s Class A common stock and, (ii) the sale of the net number of shares of Class A common stock underlying 20,664 restricted stock units received after giving effect to the number of shares sold to satisfy tax withholding obligations on each vesting date specified under the Skaruppa 10b5-1 Sales Plan (such total number of shares covered under clause (ii) is not determinable), and (iii) the sale of 1,155 shares of Class A common stock shares that remained unsold under the Original Skaruppa 10b5-1 Sales Plan. The Skaruppa 10b5-1 Sales Plan will remain in effect until the earlier of August 14, 2024, (2) the date on which all trades set forth in the Skaruppa 10b5-1 Sales Plan have been executed, or (3) such time as the Skaruppa 10b5-1 Sales Plan is otherwise terminated according to its terms.
Arrangement Duration	432 days
Severin Hacker Trading Arrangement, Common Stock [Member] \| Severin Hacker [Member]
Trading Arrangements, by Individual
Aggregate Available	190,000	190,000
Severin Hacker Trading Arrangement, SBH Trust, Common Stock [Member] \| Severin Hacker [Member]
Trading Arrangements, by Individual
Aggregate Available	120,000	120,000
Severin Hacker Trading Arrangement, Hacker Charitable Trust, Common Stock [Member] \| Severin Hacker [Member]
Trading Arrangements, by Individual
Aggregate Available	70,000	70,000
Matthew Skaruppa, September 2022 Plan [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Name	Matthew Skaruppa
Title	Chief Financial Officer
Adoption Date	September 8, 2022
Rule 10b5-1 Arrangement Terminated	true
Termination Date	June 9, 2023
Matthew Skaruppa, June 2023 Plan [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Name	Matthew Skaruppa
Title	Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	June 9, 2023
Matthew Skaruppa, September 2022 Plan, Common Stock [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	76,000	76,000
Matthew Skaruppa, September 2022 Plan, Restricted Stock [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	17,315	17,315
Matthew Skaruppa, Pursuant September 2022 Plan, Common Stock [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	41,764	41,764
Matthew Skaruppa, Pursuant September 2022 Plan, Vested Stock Options Unsold [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	44,000	44,000
Matthew Skaruppa, Pursuant September 2022 Plan, Restricted Stock Unvested [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	7,551	7,551
Matthew Skaruppa, June 2023 Plan, Potential Exercise Of Vested Stock Options And Associated Sale Of Common Stock [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	100,000	100,000
Matthew Skaruppa, June 2023 Plan, Restricted Stock Units Received [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	20,664	20,664
Matthew Skaruppa, June 2023 Plan, Common Stock In Addition To Net Shares From RSU Vesting [Member] \| Matthew Skaruppa [Member]
Trading Arrangements, by Individual
Aggregate Available	1,155	1,155

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation—The Unaudited Condensed Consolidated Financial Statements include the accounts of the Company and subsidiaries over which the Company has control. All intercompany transactions and balances have been eliminated.
Basis of Presentation and Accounting Principles	Basis of Presentation—The accompanying Unaudited Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) from the Company’s accounting records and reflect the consolidated financial position and results of operations for the three and six months ended June 30, 2023 and 2022. Unless otherwise specified, all dollar amounts (other than per share amounts) are referred to in thousands. Accounting Principles —The Unaudited Condensed Consolidated Financial Statements and accompanying notes are prepared in accordance with GAAP.
Use of Estimates	Use of Estimates— The preparation of Unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Unaudited Condensed Consolidated Financial Statements and accompanying notes. Significant estimates and assumptions reflected in the Unaudited Condensed Consolidated Financial Statements include, but are not limited to, useful lives of property and equipment, valuation of deferred tax assets and liabilities, stock-based compensation, common stock valuation, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives and contingent liabilities. Actual results may differ materially from such estimates. Management believes that the estimates, and judgments upon which they rely, are reasonable based upon information available to
Cash and Cash Equivalents	Cash and Cash Equivalents—Cash consists primarily of cash on hand and bank deposits. Cash equivalents consist primarily of money market accounts with maturities of three months or less at the date of acquisition and are stated at cost, which approximates fair value. The Company maintains cash deposits with financial institutions that may exceed federally insured limits at times.The Money market funds are considered Level 1 financial assets. Level 1 financial assets use inputs that are the unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.
Advertising Costs	Advertising Costs — Advertising costs were approximately $12,206 and $23,299 for the three and six months ended June 30, 2023, respectively, and $10,593 and $21,547 for the three and six months ended June 30, 2022, respectively, and are included within Sales and marketing in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss).
Income Taxes	Income Taxes— The Company’s provision for income taxes is computed by using an estimate of the annual effective tax rate, adjusted for discrete items taken into account in the relevant period, if any. Each quarter, the annual effective income tax rate is recomputed and if there are material changes in the estimate, a cumulative adjustment is made.
Concentration of Credit Risk	Concentration of Credit Risk —The Company’s concentration of credit risk relates to financial institutions holding the Company’s cash and cash equivalents and platforms with significant accounts receivable balances and revenue transactions.
Impairment of long-lived assets	Impairment of long-lived assets— The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If the sum of the estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset, an impairment loss is
Recently Issued Pronouncements Not Yet Adopted and Recently Adopted Accounting Pronouncements	Recently Issued Pronouncements Not Yet Adopted There are no recently issued accounting pronouncements that the Company has not yet adopted that they believe are applicable or would have a material impact on the financial statements of the Company. Recently Adopted Accounting Pronouncements There are no recently adopted accounting pronouncements.
Revenue	REVENUE The Company has three predominant sources of revenues; time-based subscriptions, in-app advertising placement by third parties, and the Duolingo English Test. Revenue is recognized upon transfer of control of promised products or services to users in an amount that reflects the consideration the Company expects to receive in exchange for those services. The Company does not enter into contracts with a customer that contain multiple promises that result in multiple performance obligations. Revenue is recorded net of taxes assessed by a government authority that are both imposed on and concurrent with specific revenue transactions between us and our users. Revenue from time-based subscriptions includes a stand-ready obligation to provide hosting services that are consumed by the customer over the subscription period. Users can purchase Duolingo monthly or they can purchase a six-month or year-long subscription and pay for the subscription at the time of purchase. Under the year-long subscription, users can also purchase a single plan or a family plan. The family plan includes up to six users on one subscription. Such payments are initially recorded to deferred revenue. The user has the ability to download limited content offline. However, as there is a significant level of integration and interdependency with the online functionality, the Company considers the service to be a single performance obligation for the online and offline content. The Company enters into arrangements with advertising networks to monetize the in-app advertising inventory. Revenue from in-app advertising placement is recognized at a point in time when the advertisement is placed and is based upon the amount received. Duolingo English Test revenue is generally recognized once the tests have gone through the proctoring process and a certification decision has been made. This process usually takes less than 48 hours after the test has been completed and uploaded. Customers have 21 days from the date of purchase to take the exam or their purchase will expire and revenue will be recognized. Virtually all customers complete their exams prior to expiration. Sometimes organizations may purchase tests in bulk via coupons with a one year expiration date. The Company will defer revenue from all tests that have neither been proctored nor expired. The Company’s users have the option to purchase consumable in-app virtual goods. The Company recognizes revenue over the period in which the user consumes the virtual good, which is generally within a month. The Company also recognizes revenue from Duo’s Taquería , a restaurant that opened during 2022, in the space adjacent to our headquarters in Pittsburgh. Revenue from Duo’s Taquería is recognized at a point in time when the sales are made. Principal Agent Considerations —The Company makes its application available to be downloaded through third-party digital distribution service providers. Users who purchase subscriptions also pay through the respective app stores. The Company evaluates the purchases via third-party payment processors to determine whether its revenues should be reported gross or net of fees retained by the payment processor. The Company is the principal in the transaction with the end user as a result of controlling, hosting, and integrating the delivery of the virtual items to the end user. The Company records revenue gross as a principal and records fees paid to third-party payment processors as Cost of revenues. Contract Balances —Deferred revenue mostly consists of payments we receive in advance of revenue recognition, and is mostly related to time-based subscriptions, which will be recognized into revenue over the course of the upcoming year (recognized over 12 months or less). Additionally, the Duolingo English Test has deferred revenue related to tests that have been purchased, but will not be recognized until the tests have been proctored. Disaggregation of Revenue In accordance with ASC 606, Revenue from Contracts with Customers , the Company disaggregates revenue from contracts with customers into revenue stream, which most closely depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	6 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	Jun. 30, 2023
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents	The following table shows the breakout between cash and money market funds. (In thousands) June 30, December 31, Cash $ 23,541 $ 91,189 Money market funds 655,124 516,991 Total $ 678,665 $ 608,180

REVENUE (Tables)

REVENUE (Tables)	6 Months Ended
REVENUE (Tables)	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Revenue Sources and Streams	Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Revenues: Subscription $ 95,158 $ 65,194 $ 181,343 $ 123,204 Advertising 13,061 11,218 24,696 22,966 Duolingo English Test 9,809 8,036 19,781 16,116 Other (1) 8,811 3,938 16,680 7,320 Total revenues $ 126,839 $ 88,386 $ 242,500 $ 169,606 ________________ (1) Other revenue is mainly comprised of in-app purchases of virtual goods.
Schedule of Deferred Revenues	Changes in deferred revenues were as follows: Six Months Ended June 30, (In thousands) 2023 2022 Beginning balance—January 1 $ 157,550 $ 98,267 Amount from beginning balance recognized into revenue (112,514) (69,597) Recognition of deferred revenue (88,507) (63,821) Deferral of revenue 236,224 163,345 Ending balance—June 30 $ 192,753 $ 128,194

PROPERTY and EQUIPMENT, net (Ta

PROPERTY and EQUIPMENT, net (Tables)	6 Months Ended
PROPERTY and EQUIPMENT, net (Tables)	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment consists of the following as of June 30, 2023 and December 31, 2022: (In thousands) June 30, December 31, 2022 Leasehold improvements $ 17,134 $ 15,983 Furniture, fixtures and equipment 5,675 5,204 Total property and equipment 22,809 21,187 Less: accumulated depreciation (10,238) (8,218) Total property and equipment, net $ 12,571 $ 12,969 Depreciation expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Research and development $ 409 $ 463 $ 816 $ 597 Sales and marketing 45 59 93 78 General and administrative 557 166 1,111 578 Total $ 1,011 $ 688 $ 2,020 $ 1,253

INTANGIBLE ASSETS AND GOODWILL

INTANGIBLE ASSETS AND GOODWILL (Tables)	6 Months Ended
INTANGIBLE ASSETS AND GOODWILL (Tables)	Jun. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Intangible assets consist mostly of capitalized software, with $117 and $18 of other intangible assets as of June 30, 2023 and December 31, 2022, respectively. (In thousands) June 30, December 31, 2022 Intangible assets $ 19,794 $ 16,827 Less: accumulated amortization (9,398) (8,330) Intangible assets, net $ 10,396 $ 8,497
Finite-lived Intangible Assets Amortization Expense	Amortization expense is included within the following financial statement line items within the Company’s Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Cost of revenues $ 402 $ 273 $ 805 $ 273 Sales and marketing 221 209 571 418 Total $ 623 $ 482 $ 1,376 $ 691

INCOME TAXES (Tables)

INCOME TAXES (Tables)	6 Months Ended
INCOME TAXES (Tables)	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	The Company’s income before taxes, income tax provision or benefit and effective tax rates were as follows: Three Months Ended June 30, Six Months Ended June 30, (In thousands, except percentages) 2023 2022 2023 2022 Income (loss) before income taxes $ 2,410 $ (14,904) $ (288) $ (27,030) (Benefit) provision for income taxes (1,315) 141 $ (1,431) $ 169 Effective tax rate (54.6) % (0.9) % 496.9 % (0.6) %

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	6 Months Ended
STOCK-BASED COMPENSATION (Tables)	Jun. 30, 2023
Equity [Abstract]
Share-based Payment Arrangement, Option, Activity	A summary of stock option activity under the Plans was as follows: (In thousands, except prices and years) Number of Weighted- Weighted- average remaining contractual life (years) Aggregate intrinsic value Options outstanding at January 1, 2023 4,410 $ 14.04 6.25 $ 251,832 Granted (1) — Exercised (916) 9.23 Forfeited and expired (26) 13.63 Options outstanding at June 30, 2023 3,468 $ 15.31 6.03 $ 443,657 Options exercisable at June 30, 2023 3,076 $ 14.63 5.90 $ 394,674 ________________ (1) There were no stock options granted during the six months ended June 30, 2023.
Share-based Payment Arrangement, RSU, Activity	A summary of RSU activity under the Plans was as follows: (In thousands, except prices) Restricted stock units Weighted- Outstanding at January 1, 2023 2,036 $ 85.74 Granted 708 131.32 Released (254) 84.91 Forfeited (117) 93.00 Outstanding at June 30, 2023 2,373 $ 99.07
Share-based Payment Arrangement, Payment Award	Tranche Company Stock Price Hurdle Number of RSUs Eligible to Vest 1 $ 127.50 90 2 $ 153.00 90 3 $ 178.50 90 4 $ 204.00 180 5 $ 255.00 180 6 $ 306.00 180 7 $ 357.00 180 8 $ 408.00 180 9 $ 612.00 270 10 $ 816.00 360
Share-based Payment Arrangement, Expensed, Amount	Stock based compensation expense is included in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) as shown in the following table: Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2023 2022 2023 2022 Cost of revenues $ 14 $ 10 $ 25 $ 16 Research and development 10,978 5,773 20,324 9,405 Sales and marketing 969 595 1,748 943 General and administrative 11,753 11,736 22,690 22,336 Total $ 23,714 $ 18,114 $ 44,787 $ 32,700

ACCRUED EXPENSES AND OTHER CU_2

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	6 Months Ended
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	Jun. 30, 2023
Other Liabilities Disclosure [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following: (In thousands) June 30, December 31, 2022 Obligations under current leases $ 6,053 $ 4,903 Marketing related accruals 3,993 3,464 Employee-related costs 2,726 4,233 Sales and VAT tax accrual 2,476 2,396 Other 6,738 6,974 Total $ 21,986 $ 21,970

EARNINGS (LOSS) PER SHARE (Tabl

EARNINGS (LOSS) PER SHARE (Tables)	6 Months Ended
EARNINGS (LOSS) PER SHARE (Tables)	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	As the liquidation and dividend rights are identical for Class A and Class B common stock, the undistributed earnings are allocated on a proportional basis and the resulting net income (loss) per share attributable to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. Three Months Ended June 30, Six Months Ended June 30, (In thousands, except per share data) 2023 2022 2023 2022 Numerator: Net income (loss) attributable to Class A and Class B common stockholders $ 3,725 $ (15,045) $ 1,143 $ (27,199) Denominator: Weighted-average shares in computing net income (loss) per share attributable to Class A and Class B common stockholders, basic and diluted 41,222 39,274 40,921 38,934 Effect of dilutive securities Founder awards where performance has been met 180 — 180 — Dilutive effect of stock options outstanding (1) 3,097 — 3,097 — RSUs outstanding 2,373 — 2,373 — Denominator for dilutive net income per common share - weighted-average shares 46,872 39,274 46,571 38,934 Basic income (loss) per common share $ 0.09 $ (0.38) $ 0.03 $ (0.70) Diluted income (loss) per common share $ 0.08 $ (0.38) $ 0.02 $ (0.70) ________________ (1) The Company had 3.5 million options outstanding as of June 30, 2023. The estimated dilutive effect is calculated as the number of shares expected to be issued upon vesting or exercise, adjusted for the strike price proceeds that are received by the Company and assumed to be used to repurchase shares of Duolingo common stock.
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the period presented because including them would have been antidilutive are as follows: (In thousands) June 30, 2022 Founder awards where performance has been met 180 Stock options outstanding (1) 4,967 RSUs outstanding (1) 1,822 Total 6,969 ________________ (1) Prior year amounts were adjusted in the current year table to include unvested options and RSUs.

DESCRIPTION OF THE BUSINESS A_2

DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Details)	Jun. 30, 2023 language
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of languages, more than	40

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 678,665	$ 608,180
Cash
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	23,541	91,189
Money market funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 655,124	$ 516,991

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Concentration Risk [Line Items]
Advertising costs	$ 12,206	$ 10,593	$ 23,299	$ 21,547
Accounts Receivable \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk (in percent)			68%		56.20%
Accounts Receivable \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk (in percent)			18.40%		27.50%
Revenue Benchmark \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk (in percent)	58.20%	53.50%	57.70%	52.30%
Revenue Benchmark \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk (in percent)	26.10%	28.40%	26.20%	28.80%
Revenue Benchmark \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk (in percent)	11.90%		11.90%

REVENUE - Narrative (Details)

REVENUE - Narrative (Details)	Jun. 30, 2023 sourceOfRevenue user
Disaggregation of Revenue [Line Items]
Number of sources of revenue \| sourceOfRevenue	3
Number of users \| user	6
Number of hours to make certification decision (less than)	48 hours
Number of days to take exam	21 days
Expiration period to take exams (in years)	1 year
Minimum
Disaggregation of Revenue [Line Items]
Subscription period (in years)	6 months
Maximum
Disaggregation of Revenue [Line Items]
Subscription period (in years)	1 year

REVENUE - Disaggregation of Rev

REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 126,839	$ 88,386	$ 242,500	$ 169,606
Transferred over Time \| Subscription
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	95,158	65,194	181,343	123,204
Transferred over Time \| Advertising
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	13,061	11,218	24,696	22,966
Transferred over Time \| Duolingo English Test
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	9,809	8,036	19,781	16,116
Transferred over Time \| Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 8,811	$ 3,938	$ 16,680	$ 7,320

REVENUE - Deferred Revenue Roll

REVENUE - Deferred Revenue Rollforward (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Revenue from Contract with Customer, Liability [Roll Forward]
Beginning balance	$ 157,550	$ 98,267
Amount from beginning balance recognized into revenue	(112,514)	(69,597)
Recognition of deferred revenue	(88,507)	(63,821)
Deferral of revenue	236,224	163,345
Ending balance	$ 192,753	$ 128,194

PROPERTY and EQUIPMENT, net - S

PROPERTY and EQUIPMENT, net - Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 22,809	$ 21,187
Less: accumulated depreciation	(10,238)	(8,218)
Total property and equipment, net	12,571	12,969
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	17,134	15,983
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,675	$ 5,204

PROPERTY and EQUIPMENT, net -_2

PROPERTY and EQUIPMENT, net - Summary of Depreciation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Line Items]
Total	$ 1,011	$ 688	$ 2,020	$ 1,253
Research and development
Property, Plant and Equipment [Line Items]
Total	409	463	816	597
Sales and marketing
Property, Plant and Equipment [Line Items]
Total	45	59	93	78
General and administrative
Property, Plant and Equipment [Line Items]
Total	$ 557	$ 166	$ 1,111	$ 578

INTANGIBLE ASSETS AND GOODWIL_2

INTANGIBLE ASSETS AND GOODWILL - Capitalized Software (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets	$ 19,794	$ 16,827
Less: accumulated amortization	(9,398)	(8,330)
Intangible assets, net	$ 10,396	$ 8,497

INTANGIBLE ASSETS AND GOODWIL_3

INTANGIBLE ASSETS AND GOODWILL - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Other intangible assets	$ 117	$ 18
Capitalized software development costs	3,176		$ 2,534
Goodwill	4,050	4,050
Goodwill, tax deductible amount	$ 3,848	$ 3,983

INTANGIBLE ASSETS AND GOODWIL_4

INTANGIBLE ASSETS AND GOODWILL - Schedule of Capitalized Software Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	$ 623	$ 482	$ 1,376	$ 691
Cost of revenues
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	402	273	805	273
Sales and marketing
Finite-Lived Intangible Assets [Line Items]
Amortization of capitalized computer software	$ 221	$ 209	$ 571	$ 418

INCOME TAXES - Effective Income

INCOME TAXES - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income (loss) before income taxes	$ 2,410	$ (14,904)	$ (288)	$ (27,030)
(Benefit) provision for income taxes	$ (1,315)	$ 141	$ (1,431)	$ 169
Effective income tax rate	(54.60%)	(0.90%)	496.90%	(0.60%)

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) $ / shares in Units, shares in Thousands, $ in Thousands			1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 01, 2023 shares	Jan. 01, 2022	Jun. 30, 2021 shares	Jun. 30, 2023 USD ($) day shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) day tranche $ / shares shares	Jun. 30, 2022 USD ($)	Jul. 26, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value, exercised						$ 106,750	$ 95,677
Unrecognized compensation cost, options				$ 3,308		3,308
Unrecognized compensation cost				$ 220,836		$ 220,836
Closing trading price, specified calendar day \| day				60		60
Compensation expense				$ 23,714	$ 18,114	$ 44,787	32,700
Stock-based compensation expense				$ 23,714	18,114	$ 44,787	32,700
Stock options outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, weighted-average period of recognition (in years)						1 year
Number of options available for grant (in shares) \| shares				9,570		9,570
RSUs outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, weighted-average period of recognition (in years)						3 years
Unrecognized compensation expense, excluding options				$ 217,528		$ 217,528
Equity instruments other than options, grants in period (in shares) \| shares						708
Performance Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, excluding options				49,123		$ 49,123
Performance Based RSUs \| 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense				7,094	$ 8,108	$ 14,234	$ 16,127
Performance Based RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period (in years)						3 years 6 months 29 days
Performance Based RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period (in years)						5 years 11 months 1 day
Performance Based RSUs \| Founders
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, excluding options				$ 110,817		$ 110,817
Equity instruments other than options, grants in period (in shares) \| shares			1,800
Settlement period after vesting (in years)			1 year
Award vesting percentage (in percent)			25%
Number of tranches \| tranche						10
Award service period (in years)			10 years
Performance Based RSUs \| Founders \| Tranche One and Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of tranches \| tranche						2
Performance Based RSUs \| Share-Based Payment Arrangement, Founders
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in usd per share) \| $ / shares						$ 61.56
2021 Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares) \| shares								7,946
Share-based compensation, shares outstanding increase, maximum amount (in percent)		5%
Additional shares authorized (in shares) \| shares	2,018
Employee Stock Purchase Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares) \| shares								1,119
Additional shares authorized (in shares) \| shares	319
2011 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						4 years
Share-based compensation, term of award (in years)						10 years

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Number of options
Options outstanding, beginning balance (in shares) \| shares	4,410
Granted (in shares) \| shares	0
Exercised (in shares) \| shares	(916)
Forfeited and expired (in shares) \| shares	(26)
Options outstanding, ending balance (in shares) \| shares	3,468	4,410
Number of options exercisable (in shares) \| shares	3,076
Weighted- average exercise price
Outstanding, beginning balance (in usd per share) \| $ / shares	$ 14.04
Granted (in usd per share) \| $ / shares
Exercised (in usd per share) \| $ / shares	9.23
Forfeited and expired (in usd per share) \| $ / shares	13.63
Outstanding, ending balance (in usd per share) \| $ / shares	15.31	$ 14.04
Weighted average exercise price, options exercisable (in usd per share) \| $ / shares	$ 14.63
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (in years), outstanding	6 years 10 days	6 years 3 months
Weighted average remaining contractual term (in years), exercisable	5 years 10 months 24 days
Aggregate intrinsic value, outstanding \| $	$ 443,657	$ 251,832
Aggregate intrinsic value, exercisable \| $	$ 394,674

STOCK-BASED COMPENSATION - Sche

STOCK-BASED COMPENSATION - Schedule of Restricted Stock Unit Activity (Details) - RSUs outstanding - $ / shares shares in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Restricted stock units
Beginning balance (in shares)	2,373	2,036
Granted (in shares)	708
Released (in shares)	(254)
Forfeited (in shares)	(117)
Ending balance (in shares)	2,373
Weighted- average grant date fair value per share
Beginning balance (in usd per share)	$ 85.74
Granted (in usd per share)	131.32
Released (in usd per share)	84.91
Forfeited (in usd per share)	93
Ending balance (in usd per share)	$ 99.07

STOCK-BASED COMPENSATION - Sc_2

STOCK-BASED COMPENSATION - Schedule of Payment Award (Details) - RSUs outstanding shares in Thousands	Jun. 30, 2023 $ / shares shares
1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 127.50
Number of RSUs Eligible to Vest (in shares) \| shares	90
2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 153
Number of RSUs Eligible to Vest (in shares) \| shares	90
3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 178.50
Number of RSUs Eligible to Vest (in shares) \| shares	90
4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 204
Number of RSUs Eligible to Vest (in shares) \| shares	180
5
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 255
Number of RSUs Eligible to Vest (in shares) \| shares	180
6
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 306
Number of RSUs Eligible to Vest (in shares) \| shares	180
7
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 357
Number of RSUs Eligible to Vest (in shares) \| shares	180
8
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 408
Number of RSUs Eligible to Vest (in shares) \| shares	180
9
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 612
Number of RSUs Eligible to Vest (in shares) \| shares	270
10
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company Stock Price Hurdle (in usd per share) \| $ / shares	$ 816
Number of RSUs Eligible to Vest (in shares) \| shares	360

STOCK-BASED COMPENSATION - Sc_3

STOCK-BASED COMPENSATION - Schedule of Income Statement Location for Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 23,714	$ 18,114	$ 44,787	$ 32,700
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	14	10	25	16
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	10,978	5,773	20,324	9,405
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	969	595	1,748	943
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 11,753	$ 11,736	$ 22,690	$ 22,336

ACCRUED EXPENSES AND OTHER CU_3

ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Other Liabilities Disclosure [Abstract]
Obligations under current leases	$ 6,053	$ 4,903
Marketing related accruals	3,993	3,464
Employee-related costs	2,726	4,233
Sales and VAT tax accrual	2,476	2,396
Other	6,738	6,974
Total	$ 21,986	$ 21,970

EMPLOYEE BENEFIT PLAN (Details)

EMPLOYEE BENEFIT PLAN (Details) - USD ($)	3 Months Ended		6 Months Ended
EMPLOYEE BENEFIT PLAN (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, contributions by employer	$ 1,473,000	$ 1,059,000	$ 2,870,000	$ 2,042,000
Defined contribution plan, employer discretionary contribution amount	$ 0	$ 0	$ 0	$ 0
First 4% of Employee Elective Deferral
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match (in percent)			100%
Employer matching contribution, percent of employees' gross pay (in percent)			4%
Next 2% of Employee Elective Deferral
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match (in percent)			50%
Employer matching contribution, percent of employees' gross pay (in percent)			2%

EARNINGS (LOSS) PER SHARE - Nar

EARNINGS (LOSS) PER SHARE - Narrative (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2023 votePerShare shares	Jun. 30, 2022 shares
Performance Based RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Founder awards where performance not met (in shares) \| shares	1,620	1,620
Common Class A
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Voting rights, per share	1
Common Class B
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Voting rights, per share	20

EARNINGS (LOSS) PER SHARE - Sch

EARNINGS (LOSS) PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Numerator:
Net income (loss) attributable to Class A and Class B common stockholders	$ 3,725	$ (15,045)	$ 1,143	$ (27,199)
Denominator:
Weighted-average shares in computing net income (loss) per share attributable to Class A and Class B common stockholders, diluted (in shares)	46,872	39,274	46,571	38,934
Effect of dilutive securities
Basic loss per common share (in usd per share)	$ 0.09	$ (0.38)	$ 0.03	$ (0.70)
Diluted loss per common share (in usd per share)	$ 0.08	$ (0.38)	$ 0.02	$ (0.70)
Options outstanding (in shares)	3,468		3,468		4,410
Founder awards where performance has been met
Effect of dilutive securities
Stock options and RSUs outstanding (in shares)	180	0	180	0
Stock options outstanding
Effect of dilutive securities
Stock options and RSUs outstanding (in shares)	3,097	0	3,097	0
RSUs outstanding
Effect of dilutive securities
Stock options and RSUs outstanding (in shares)	2,373	0	2,373	0
Class A and Class B Common Stock
Denominator:
Weighted-average shares in computing net income (loss) per share attributable to Class A and Class B common stockholders, basic (in shares)	41,222	39,274	40,921	38,934
Weighted-average shares in computing net income (loss) per share attributable to Class A and Class B common stockholders, diluted (in shares)	41,222	39,274	40,921	38,934

EARNINGS (LOSS) PER SHARE - S_2

EARNINGS (LOSS) PER SHARE - Schedule of Antidilutive Securities (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2022 shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	6,969
Founder awards where performance has been met
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	180
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	4,967
RSUs outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computation of earnings per share (in shares)	1,822