DUOL

Business Context and Reporting Period

Company: Duolingo, Inc.
Filing Type: Form 10-Q (Unaudited)
Reporting Period: Quarter and nine months ended September 30, 2025
Business Overview: Duolingo operates a freemium mobile learning platform offering courses in over 40 languages, alongside the Duolingo English Test. The company generates revenue through subscriptions, advertising, in-app purchases, and testing services.

Key Financial Metrics

Operating Metrics (Q3 2025):

• Monthly Active Users (MAUs): 135.3 million (+20% YoY)
• Daily Active Users (DAUs): 50.5 million (+36% YoY)
• Paid Subscribers: 11.5 million (+34% YoY)
• Subscription Bookings: $240.3 million (+36% YoY)

Material Changes vs. Prior Period

• Revenue Growth: Total revenue increased 41% in Q3 and 40% over the nine months, driven primarily by a 46% increase in subscription revenue and a 21% increase in advertising revenue.
• Profitability Surge: Net income increased significantly (over 1,000% in Q3) primarily due to a one-time income tax benefit of $222.7 million resulting from the release of the valuation allowance on deferred tax assets. Excluding this item, net income growth was driven by revenue expansion.
• Expense Increases: Operating expenses rose 28% in Q3 and 31% over nine months. Research and Development (R&D) expenses increased 32% (Q3) due to headcount growth and stock-based compensation. Sales and Marketing expenses increased 37% (Q3) due to higher direct marketing spend.
• Gross Margin Compression: Gross margin decreased slightly to 72.5% in Q3 (from 72.9%) and 72.0% for the nine months (from 73.1%), attributed to increased generative AI costs for the Duolingo Max tier and higher hosting fees.
• Acquisitions: The company completed an acquisition in July 2025 for $34.5 million (cash consideration), adding design and engineering talent. This resulted in $24.8 million of goodwill and $8.3 million of intangible assets.

Guidance, Outlook, and Risks

Management Commentary: Management attributes growth to product initiatives enhancing social engagement, marketing efforts, and course improvements. The company continues to invest heavily in R&D to drive user engagement and monetization. The release of the tax valuation allowance was based on ten consecutive quarters of pre-tax income and sustained operational profitability.

Forward-Looking Risks:

• User Retention & Engagement: Ability to retain users and sustain engagement in a competitive market.
• Technology & AI: Success of AI and machine learning implementations and reliance on third-party cloud providers.
• Regulatory & Tax: Fluctuations in effective tax rates and changes in tax laws (e.g., immediate expensing of R&D under the "One Big Beautiful Bill Act").
• Platform Dependence: Reliance on Apple and Google for distribution and payment processing (Apple and Google processed ~85.5% of Q3 revenue).

Unusual Items: The Q3 2025 net income includes a discrete tax benefit of $222.7 million from the release of the valuation allowance, which is not indicative of ongoing operating performance.

Investor Verification Checklist

• Tax Benefit Sustainability: Verify the assumptions behind the release of the deferred tax asset valuation allowance and the likelihood of future tax provisions returning to normal levels.
• AI Cost Trajectory: Monitor the impact of generative AI costs on gross margins as the Duolingo Max tier expands.
• Acquisition Integration: Assess the return on investment for the July 2025 acquisition and the associated integration costs.
• Platform Concentration: Evaluate risks associated with the heavy reliance on Apple and Google for revenue processing and user acquisition.
• Non-GAAP Reconciliation: Review the reconciliation of Adjusted EBITDA ($80.0M for Q3) to understand the impact of stock-based compensation and acquisition costs on core operating performance.