The free version now available is Claude 4 Sonnet. The paid version, which comes with its $20/month Pro plan, is Claude 4 Opus. Opus is also available to those using Anthropic's even more ...

starting with Opus 4 and Sonnet 4, which the company said set new standards for coding, advanced reasoning and AI agents. Opus is the company’s most powerful model yet, designed to sustain the ...

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 ...

Anthropic has introduced its next-generation AI models: Claude Opus 4 and Claude Sonnet 4. These models offer two modes, quick responses and deeper thinking for complex problems. They are ...

Anthropic today announced the next generation of Claude models: Claude Opus 4 and Claude Sonnet 4. Anthropic claims that its flagship Claude Opus 4 is the world’s best coding model and excels in ...

A new Anthropic report shows exactly how in an experiment, AI arrives at an undesirable action: blackmailing a fictional ...

While it’s not as powerful as Opus 4, Sonnet 4 still delivers strong performance—outscoring even Opus in some SWE-bench configurations (72.7%). Its value lies in combining speed with reliability.

Contextual Persistence: Higher-agency systems maintain awareness of project goals across multiple interactions. While code ...

Overall, Claude Opus 4 is a top-notch tool for tackling challenging coding tasks. On the other hand, Claude Sonnet 4 is a crucial improvement over its previous version, exceling in coding with ...