Claude Opus 5.5
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5.
Specifications
| Lab | Anthropic |
|---|---|
| Context window | 1M tokens |
| Input price | $4.00/1M |
| Output price | $20.00/1M |
| Release | Sep 2026 |
Strengths
- Flagship reasoning and coding capability
- 1M-token context window
- Strong long-horizon agent positioning
Weaknesses
- High output-token price
- Limited independent evaluation data
Best for
- Large codebase changes
- Complex research
- Long-running agents
In Depth: Claude Opus 5.5
Summary
Claude Opus 5.5 is an AI model from Anthropic.
Released in Sep 2026. It takes text, image, and file input and produces text output, with a context window of 1M tokens. Input pricing is $4.00 per 1M tokens and output is $20.00 per 1M tokens on OpenRouter.