ChatGPT Hits 400 Million Weekly Users as AI Adoption Increases, a16z Reports

OpenAI’s ChatGPT has doubled its weekly active users in less than six months, reaching 400 million in February 2025, according to a new report by VC firm Andreessen Horowitz (a16z). 

The report suggested that growth had initially plateaued from March 2023 to April 2024 but surged after new features were introduced.

The rapid increase follows the release of new models and features, including GPT-4o’s multimodal capabilities, which drove a surge in usage between April and May 2024. Advanced Voice Mode further boosted engagement from July to August, while the o1 model series led to increased adoption from September to October.

ChatGPT’s mobile usage has also seen steady growth, with users increasing by 5% to 15% each month over the past year. Of its 400 million weekly active users, 175 million now access ChatGPT on mobile.

In terms of usage and monetisation, competition is intensifying, with China’s DeepSeek reaching No. 2 globally within 10 days of launch and capturing 15% of ChatGPT’s mobile user base by February. Overall, it still lags ChatGPT. 

Deepseek also reported a theoretical daily profit margin of 545% for its inference services, despite limitations in monetisation and discounted pricing structures.

Another observation from the report includes how the most-used AI apps aren’t always the most profitable, and many niche AI tools generate higher revenue per user. 

Industries like photo editing, nutrition, and language learning have high revenue potential despite smaller user bases. Subscription-based AI services rank higher in revenue than mass-market AI apps.