anthropic/claude-opus-5.5Claude Opus 5.5 is Anthropic’s proprietary AI model, released Sep 22, 2026. It scores 169 on the Epoch Capabilities Index, costs $4/M input and $20/M output tokens, and handles a 1M-token context window. Its strongest use case is coding, where it ranks in the 100th percentile of the models Model Beat tracks.
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5.
Scores on standardized evaluations. Higher is better — and rank shows where Claude Opus 5.5 lands among all models tracked on Model Beat.
Abstract visual reasoning
Harder abstract reasoning
Graduate-level scientific reasoning
Frontier of human expert knowledge
Common-sense trick questions
Factual accuracy & hallucination
Scientific research coding
Human-rated web development
Olympiad-qualifier math
Multi-step agentic tasks
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5.
Claude Opus 5.5 is an AI model developed by Anthropic, part of the Claude family, released Sep 22, 2026.
Claude Opus 5.5's list price from Anthropic is $4 per million input tokens and $20 per million output tokens.
Claude Opus 5.5 supports a context window of up to 1M tokens.
On standardized evaluations tracked by Epoch AI, Claude Opus 5.5 scores 61.4% on Humanity's Last Exam, 66.9% on SciCode, 1820 on WebDev Arena.
Claude Opus 5.5 is a proprietary model (API access), available through its provider's API rather than as a downloadable open-weight model.
Benchmark data from Epoch AI (CC BY) and Artificial Analysis; pricing, specs & descriptions from OpenRouter. Data updated Nov 12, 2026.