Claude Opus 5.5 vs Claude Opus 5
Claude Opus 5.5 is from Anthropic, released September 22, 2026. Claude Opus 5 is from Anthropic, released July 24, 2026.
- LMArena Elo1504 vs 1491. Claude Opus 5.5 is 0.9% ahead on LMArena Elo.
- Input per 1M$4 vs $5. Claude Opus 5.5 costs 20% less per million input tokens.
- Output per 1M$20 vs $25. Claude Opus 5.5 costs 20% less per million output tokens.
- Context window1M vs 1M. Both hold 1M tokens of context.
Prices are the vendors’ published API rates; Elo is LMArena’s text board. Each figure is dated on its model page.
Interactive Comparison
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$4 / $20 per 1M tokens | $5 / $25 per 1M tokens | |
|---|---|---|
| Identity | ||
| Developer | Anthropic | Anthropic |
| Released | Sep 2026 | Jul 2026 |
| Status | GA | GA |
| Licence | Proprietary | Proprietary |
| Self-hostable | No | No |
| Cost | ||
| Blended $/1M tokensinput × 0.75 + output × 0.25 | $8.000 / 1M tokens | $10.000 / 1M tokens |
| Input price | $4.000 / 1M tokens | $5.000 / 1M tokens |
| Output price | $20.000 / 1M tokens | $25.000 / 1M tokens |
| Cached input | $0.20 per 1M tokens | $0.50 / 1M tokens (cache hit) |
| Batch discount | 50% ($2 / $10 per 1M tokens) | 50% off input/output (Batch API) |
| Free tier | — | Small trial credit for new accounts, no ongoing free tier |
| Capacity | ||
| Context window | 1M tokens | 1M tokens |
| Max output | 128k tokens | 128k tokens |
| Long-context surcharge | — | None (full 1M window at standard pricing) |
| Capability | ||
| Vision in | Yes | Yes |
| Audio in | No | No |
| Function calling | Yes | Yes |
| Structured output | Yes | Yes |
| Extended reasoning | Yes | Yes |
| Web search | Yes | Yes |
| Code execution | Yes | Yes |
| Access | ||
| API | Yes | Yes |
| Chat app | Yes | Yes |
| Cloud marketplaces | Amazon Bedrock, Google Cloud, Microsoft Foundry | AWS Bedrock, Google Cloud, Microsoft Foundry |
| Fine-tuning | No | No |
| Measured quality | ||
| LMArena Elo | 1504 (checked Oct 2026) | 1491 (checked Sep 2026) |
| LMArena rank | Rank 4 | Rank 11 |
| GPQA Diamond | — | 93 |
| Elo per dollarLMArena Elo ÷ blended $/1M tokens | 188 | 149 |
