Claude Opus 5.5
Anthropic · Released Sep 22, 2026
$4
Input price / MTok
#27 of 36$20
Output price / MTok
#27 of 361.0M
Context window
#10 of 37Summary
Claude Opus 5.5 is a proprietary language model from Anthropic, released on Sep 22, 2026.
At $4 input and $20 output per million tokens, it ranks #27 of 36 for input price, placing it mid-range on input cost.
Its context window of 1.0M tokens ranks #10 of 37 for context depth in this dataset.
It targets coding, agents, reasoning workloads.
Released Sep 22 2026. Anthropic's docs recommend it as the starting model for most workloads, built for long-running agentic coding and knowledge work, and point to Fable 5.1 when Opus 5.5 at higher effort still falls short. Adaptive thinking is always on (default effort medium). Priced below Opus 5 ($5/$25). API identifier claude-opus-5-5, reliable knowledge cutoff June 2026, retirement not sooner than Sep 22 2027. Source: https://platform.claude.com/docs/en/models/opus-5-5/overview (checked 2026-09-26).
No independently verified benchmark scores are available for this model. Scores are only shown when independently confirmed with a source URL.