Claude Opus 5.5
Anthropic's flagship for reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. 1M context, 128K max output, and a lower rack rate than Opus 5.
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Context
1M
Weights
Closed
API only
Input
$4
/1M tok
Output
$20
/1M tok
Cache read
$0.20
0.05x input
Cache write
$5
1.25x input
Price & speed via Artificial Analysis · ranked across tracked models · caching via OpenRouter
| Reasoning effort | Index | Speed |
|---|---|---|
| max | 57.6 | 97 t/s |
| xhigh | 56.0 | 76 t/s |
| high | 53.6 | 72 t/s |
| medium | 51.2 | 70 t/s |
| low | 42.3 | 69 t/s |
Intelligence Index per reasoning-effort setting, via Artificial Analysis · pricing identical across tiers
Reported on 12 evals across 8 domains - best 100.0% on ProofBench · #1 of 74