ChatGPT hits 1 billion monthly users, fastest ever

Market data from Sensor Tower shows ChatGPT has reached 1 billion monthly active users worldwide, faster than any app before. It hit the milestone in May, about three years after launch, beating the growth speed of Google Maps, TikTok, Instagram, and YouTube.

Even with growing competition from Anthropic, this shows ChatGPT still leads the AI space. Anthropic has secretly filed for its US IPO this week, and OpenAI is also planning to finalize its IPO plans in the coming weeks.

But Anthropic's chatbot Claude is growing fast: it had 56 million monthly users in Q2 2026, up about 640% from last year, way above ChatGPT's 62% growth. In the US, ChatGPT users who also installed Claude spent 5% less time on ChatGPT a month later compared to their average over the previous eight months, showing competition is changing how people use these tools.