Claude Opus 5.5 vs GPT-5.6 Sol
Claude Opus 5.5 (Anthropic) and GPT-5.6 Sol (OpenAI) compared on price, context window, speed and independent benchmarks. Claude Opus 5.5 scores higher on the Artificial Analysis Intelligence Index (57.6 vs 47), while GPT-5.6 Sol is 1.0× cheaper on a blended basis. Pick Claude Opus 5.5 for the hardest tasks and GPT-5.6 Sol when cost dominates.
| Claude Opus 5.5 | GPT-5.6 Sol | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input $/1M | $4.00 | $4.00 |
| Output $/1M | $20.0 | $20.0 |
| Blended $/1M (3:1) | $8.00 | $8.00 |
| Cached input $/1M | $0.20 | $0.40 |
| Context window | 1M | 1.1M |
| Knowledge cutoff | 2026-06 | 2026-02 |
| License | proprietary | proprietary |
| Speed (tok/s) | 85 | 58 |
| Artificial Analysis Intelligence Index | 57.6 | 47 |
| LMArena Elo | — | 1455 |
| GPQA Diamond | — | 94.1% |
| Humanity's Last Exam | 61.4% | 49.5% |