According to Similarweb, Anthropic’s Claude website traffic jumped roughly 770% between September 2024 and March 2026, while ChatGPT’s web visits grew about 84% over the same period, meaning Claude expanded at roughly nine times the pace of OpenAI’s chatbot. However, new Similarweb audience overlap data shows that the vast majority of Claude users also use ChatGPT in the same month, while only a relatively small share of ChatGPT users also visit Claude. The two datasets suggest Claude’s rapid growth is not primarily from users abandoning ChatGPT, but rather users adding Claude alongside OpenAI’s chatbot. Similarweb says the generative AI landscape has evolved from a single-platform market into a genuinely competitive one. ChatGPT is estimated to have around 1 billion monthly active users, while Claude has roughly 56 million. The article notes that for investors, the more important takeaway may be how consumers are using multiple AI assistants for different tasks, which could explain why companies across the AI ecosystem continue investing aggressively.