Claude Opus 4
Anthropic's flagship model at launch, built for sustained, long-horizon agentic work
Claude Opus 4 launched on May 22, 2025 as Anthropic’s flagship model, released alongside the smaller Claude Sonnet 4. It was built for sustained, long-horizon agentic work such as multi-hour coding sessions and research tasks that involve using tools repeatedly across a long thread, rather than answering a single prompt. Anthropic reported it leading on SWE-bench Verified at launch, at roughly 72.5 percent, and it can use tools, including web search, during extended thinking and run several tools in parallel. It runs on a 200,000 token context window, reads images as well as text, and is priced at $15 per million input tokens and $75 per million output tokens, the same rate Anthropic had charged for Claude 3 Opus a year earlier.