Anthropic releases Claude Opus 5.5: Fable 5.1-level work at most tasks, 40% cheaper to run than Opus 5

Anthropic released Claude Opus 5.5, the first model in the Claude 5.5 family, positioned as Fable 5.1-level performance at a lower Opus-level price. The stated price and cost comparator is Opus 5, and Fable 5.1 and GPT-6 Astra are described as models that raised capability expectations. The stated comparison is that Opus 5.5 performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.

Opus 5.5 is priced at $4/$20 per million input/output tokens, with cache pricing at $0.20. That is 20% lower than Opus 5, and the cache price is 60% lower. Anthropic estimates typical overall costs will drop 40% and speed rise 30%; fast mode is priced at $8/$40 with up to 2.5x the speed.

On capability, the company highlights agentic coding, security and communication, and says Opus 5.5 can run on its own for extended periods with increased reliability. The communication changes address the most common feedback on Opus 5, putting the most important information up front and following given writing rules. Early-tester blurbs are flagged as AI generated and grouped by feature area, praising agentic coding skills, efficiency, readability and communication.

The report rests on a release summary covering official pricing, cost and speed estimates, zero data retention support, and guardrails described as similar to Fable 5.1; benchmark detail and the full technical explanation fall outside the summary.

The benchmarks are described as excellent, but the release summary also advises not to rely on them, and occasional spots remain where Astra or Fable is still ahead; the 40% cost drop and 30% speed gain are company estimates rather than measurements.