Free, Pro, Max, Team, and Enterprise Claude plans can access Claude Sonnet 4 and Opus 4 now, with an extended thinking mode in beta.

Anthropic claims Claude Opus 4 can compete with GPT-4.1 and Gemini 2.5, while Sonnet 4 outperforms its predecessor in reasoning and code generation

Claude 4 Sonnet is a leaner model, with improvements built on Anthropic's Claude 3.7 Sonnet model. The 3.7 model often had problems with overeagerness and sometimes did more than the person asked it to do, Amodei said. While it's a less resource-intensive model, it still performs well, he said.