Claude Opus 4.5 vs Claude Opus 5.5
Claude Opus 5.5 is cheaper on output tokens, while Claude Opus 5.5 offers a larger context window. Choose Claude Opus 4.5 or Claude Opus 5.5 based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Claude Opus 4.5 | Claude Opus 5.5 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Input / 1M tokens | $5.00 | $4.00 |
| Output / 1M tokens | $25.00 | $20.00 |
| Context window | 200K | 1M |
| Parameters | — | — |
| Open weights | No | — |
| Released | Nov 2025 | — |
| LiveBench score | 76.0 | — |
| SWE-bench Verified score | 79.2 | — |
| SWE-bench Multilingual score | 70.7 | — |
| LMArena (Chatbot Arena) Elo score | 1451 | 1516 |
| LMArena WebDev Elo score | 1493 | 1811 |
| GPQA Diamond score | 86.0 | 90.6 |
| FrontierMath score | 20.7 | — |
| Epoch Capabilities Index score | 150 | 167 |
| LMArena Vision Elo score | — | 1321 |
FAQ
Is Claude Opus 4.5 or Claude Opus 5.5 cheaper?
Claude Opus 5.5 is cheaper on output tokens ($20.00 vs $25.00 per 1M).
Which has the larger context window, Claude Opus 4.5 or Claude Opus 5.5?
Claude Opus 5.5 has the larger context window (1M tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.