The company also described its new flagship as the “best coding model in the world,” with Anthropic’s benchmarks showing that Opus 4 outperformed Google’s Gemini 2.5 Pro, OpenAI’s o3 reasoning, and GPT-4.

Anthropic says Claude Opus 4 is its most powerful model and the best coding model in the world, while Sonnet 4 is replacing Sonnet 3.7 in the chatbot.

Anthropic has long been warning about these risks—so much so that in 2023, the company pledged to not release certain models until it had developed safety measures capable of constraining them. Now this system,