OpenAI’s ChatGPT is more popular than ever. The company now has 400 million weekly active users, a significant jump from 300 million in December, according to OpenAI COO Brad Lightcap. The rapid growth highlights how ChatGPT has become a mainstream AI tool, widely used across both consumer and enterprise sectors, despite rising competition from rivals like DeepSeek.
Key Points:
- ChatGPT’s user base grew 33% in three months, reaching 400 million weekly active users.
- OpenAI now has 2 million paying business users, doubling since September 2024.
- API usage has doubled in six months, with the “o3” reasoning model seeing a fivefold increase.
chatgpt recently crossed 400M WAU, we feel very fortunate to serve 5% of the world every week
— Brad Lightcap (@bradlightcap) February 20, 2025
2M+ business users now use chatgpt at work, and reasoning model API use is up 5x since o3 mini launch
we'll bring GPT-4.5 and GPT-5 to chat and the API soon, with unlimited GPT-5 for… https://t.co/7hfyUcIyBW
The surge in users extends beyond individual consumers. OpenAI’s enterprise plans have also gained traction, now boasting 2 million paying business users—doubling since September 2024. Many companies, including Uber, Morgan Stanley, and T-Mobile, are integrating ChatGPT into workflows, a shift Lightcap compared to the early days of cloud computing. “AI is going to be like cloud services. You won’t be able to run a business without it,” he said.
On the developer side, OpenAI’s API traffic has doubled in six months, with its latest “o3” reasoning model seeing a fivefold increase in adoption. This underscores the growing reliance on OpenAI’s models in software development and enterprise applications.
Despite impressive models coming from competitors like xAI, Anthropic and Google , the numbers speak for themselves. ChatGPT continues to expand its footprint across personal and professional use cases, solidifying OpenAI’s position as both a consumer tech giant and a critical frontier model provider market.