Anthropic has released Claude Opus 5.5, the first model in its new Claude 5.5 family, positioning it as a more efficient alternative to previous generations. The model is designed to perform at the level of Claude Fable 5.1 for most tasks while costing 40% less to run than Opus 5.
- Opus 5.5 offers significant improvements in writing quality by placing important information up front and strictly following user-defined writing rules.
- The model is approximately 30% faster and features a 20% reduction in base token pricing compared to Opus 5.
- It now serves as the default model in Claude Code, the Claude app, and Cowork, with a default effort setting described as comparable to Fable 5.1 on intelligence but faster.
- Anthropic reports that Opus 5.5 leads on agentic coding, computer use, and knowledge work benchmarks, beating GPT-6 Astra on most tests.
- The release includes enhanced safety safeguards for cyber, bio, and frontier LLM development, matching the class of Fable 5.1.
This update establishes Opus 5.5 as the new standard for high-efficiency tasks, offering users better speed, cost-effectiveness, and communication clarity in long sessions.