OpenAI has announced that ChatGPT has reached 400 million weekly active users, a significant increase from 300 million in December 2024. While the company did not disclose the number of paid subscribers for its Plus or Pro plans, it revealed a notable growth in enterprise engagement with 2 million paying business users, doubling since September 2024. Additionally, developer API traffic has doubled over the past six months. These developments come as China's DeepSeek introduces its own AI models and assistant app, presenting fresh competition.