SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
Jun. 30, 2026
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, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives, contingent liabilities, and valuation of goodwill and intangible assets from acquisitions. 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. Advertising Costs—Advertising costs were approximately $28,199 and $56,341 for the three and six months ended June 30, 2026, and $19,649 and $37,184 for the three and six months ended June 30, 2025, respectively, and are included within Sales and marketing in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income. 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 deposits and certificates of deposit with banks which exceed the Federal Deposit Insurance Corporation (“FDIC”) insured limit and money market accounts which are not FDIC insured. 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 revenue comes through the subscriptions and advertising streams, and payments are made to Duolingo through service providers. Three service providers, Apple, Google, and Stripe, accounted for 65.5%, 15.7%, and 11.7%, respectively, of total Accounts receivable as of June 30, 2026 and 62.5%, 22.7% and 11.4%, respectively, of total Accounts receivable as of December 31, 2025. Segment—The Company operates as a single operating segment and derives revenues from customers through time-based subscriptions, in-app advertising placement by third parties, the Duolingo English Test, and in-app purchases of virtual goods (“IAPs”). The Chief Executive Officer, as the chief operating decision maker, evaluates the Company’s performance and allocates resources based on consolidated net income, as presented in the income statement, supplemented by disaggregated revenue details. Significant segment expenses are those that are presented on the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income. The measure of segment assets is reported on the balance sheet as total consolidated assets. Accordingly, the Company has determined that it has a single reportable segment and operating segment structure, and operates as one reporting unit. 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. The Company recorded an impairment of capitalized software of $578 for the three and six months ended June 30, 2026, and no impairment was recognized during the three and six months ended June 30, 2025. Allowance for Credit Losses—The Company evaluates its cash equivalents, accounts receivable and held-to-maturity marketable securities financial assets for expected credit losses. Expected credit losses represent the portion of the amortized cost basis of a financial asset that an entity does not expect to collect. An allowance for expected credit losses is meant to reflect a risk of loss even if remote, irrespective of the expectation of collection from a particular issuer or debt security. The Company has not historically experienced any credit losses on any of its financial assets. With respect to cash equivalents and accounts receivable, given consideration of their short maturity, lack of historical losses and the current environment, the Company concluded there is generally no expected credit losses for these financial assets. With respect to held-to-maturity marketable securities which are comprised of debt securities, the Company evaluates expected credit losses on a pooled basis based on issuer-type which have similar credit risk characteristics. There is no allowance for credit losses for all periods presented. Related Parties—The Company incurred expenses with a vendor which certain members of the Company’s Board of Directors and executive officers serve as members of the vendor’s board of directors of approximately $207 and $426 during the three and six months ended June 30, 2026, respectively, and $165 and $329 during the three and six months ended June 30, 2025, respectively. As of June 30, 2026 and December 31, 2025, no amounts remained payable to the vendor. These transactions were conducted in the ordinary course of business on terms the Company believes to be comparable to those available from unaffiliated third parties and were reviewed and approved in accordance with the Company’s related person transaction policy. Recent Accounting Pronouncements Recently Issued Pronouncements Not Yet Adopted In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. The amendment requires new financial statement disclosures to provide disaggregated information for certain types of expenses, including employee compensation, depreciation, and amortization in commonly presented expense captions such as cost of revenue, sales and marketing, and general and administrative expenses. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. The Company is currently evaluating the disclosure requirements related to the new standard. In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. The amendments in this update remove all references to prescriptive and sequential software development stages (referred to as “project stages”) throughout Subtopic 350-40. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods. The Company is in the process of evaluating the effect that the adoption of this standard may have on its consolidated financial statements. Recently Adopted Accounting Pronouncements There are no recently adopted accounting pronouncements.

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, operating lease right-of-use assets and liabilities, capitalization of internally developed software and associated useful lives, contingent liabilities, and valuation of goodwill and intangible assets from acquisitions. 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.

Advertising Costs—Advertising costs were approximately $28,199 and $56,341 for the three and six months ended June 30, 2026, and $19,649 and $37,184 for the three and six months ended June 30, 2025, respectively, and are included within Sales and marketing in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income.

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 deposits and certificates of deposit with banks which exceed the Federal Deposit Insurance Corporation (“FDIC”) insured limit and money market accounts which are not FDIC insured. 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 revenue comes through the subscriptions and advertising streams, and payments are made to Duolingo through service providers. Three service providers, Apple, Google, and Stripe, accounted for 65.5%, 15.7%, and 11.7%, respectively, of total Accounts receivable as of June 30, 2026 and 62.5%, 22.7% and 11.4%, respectively, of total Accounts receivable as of December 31, 2025.

Segment—The Company operates as a single operating segment and derives revenues from customers through time-based subscriptions, in-app advertising placement by third parties, the Duolingo English Test, and in-app purchases of virtual goods (“IAPs”). The Chief Executive Officer, as the chief operating decision maker, evaluates the Company’s performance and allocates resources based on consolidated net income, as presented in the income statement, supplemented by disaggregated revenue details. Significant segment expenses are those that are presented on the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income. The measure of segment assets is reported on the balance sheet as total consolidated assets. Accordingly, the Company has determined that it has a single reportable segment and operating segment structure, and operates as one reporting unit.

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. The Company recorded an impairment of capitalized software of $578 for the three and six months ended June 30, 2026, and no impairment was recognized during the three and six months ended June 30, 2025.

Allowance for Credit Losses—The Company evaluates its cash equivalents, accounts receivable and held-to-maturity marketable securities financial assets for expected credit losses. Expected credit losses represent the portion of the amortized cost basis of a financial asset that an entity does not expect to collect. An allowance for expected credit losses is meant to reflect a risk of loss even if remote, irrespective of the expectation of collection from a particular issuer or debt security. The Company has not historically experienced any credit losses on any of its financial assets.

With respect to cash equivalents and accounts receivable, given consideration of their short maturity, lack of historical losses and the current environment, the Company concluded there is generally no expected credit losses for these financial assets. With respect to held-to-maturity marketable securities which are comprised of debt securities, the Company evaluates expected credit losses on a pooled basis based on issuer-type which have similar credit risk characteristics. There is no allowance for credit losses for all periods presented.

Related Parties—The Company incurred expenses with a vendor which certain members of the Company’s Board of Directors and executive officers serve as members of the vendor’s board of directors of approximately $207 and $426 during the three and six months ended June 30, 2026, respectively, and $165 and $329 during the three and six months ended June 30, 2025, respectively. As of June 30, 2026 and December 31, 2025, no amounts remained payable to the vendor. These transactions were conducted in the ordinary course of business on terms the Company believes to be comparable to those available from unaffiliated third parties and were reviewed and approved in accordance with the Company’s related person transaction policy.

In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. The amendment requires new financial statement disclosures to provide disaggregated information for certain types of expenses, including employee compensation, depreciation, and amortization in commonly presented expense captions such as cost of revenue, sales and marketing, and general and administrative expenses. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. The Company is currently evaluating the disclosure requirements related to the new standard.

In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. The amendments in this update remove all references to prescriptive and sequential software development stages (referred to as “project stages”) throughout Subtopic 350-40. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods. The Company is in the process of evaluating the effect that the adoption of this standard may have on its consolidated financial statements.