Claude Opus 5.5 vs Claude Fable 5.1
Claude Opus 5.5 (Anthropic) and Claude Fable 5.1 (Anthropic) compared on price, context window, speed and independent benchmarks. Claude Opus 5.5 both scores higher on the Artificial Analysis Intelligence Index (57.6 vs 53.4) and is cheaper on a blended basis — 2.5× less than Claude Fable 5.1.
| Claude Opus 5.5 | Claude Fable 5.1 | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Input $/1M | $4.00 | $10.0 |
| Output $/1M | $20.0 | $50.0 |
| Blended $/1M (3:1) | $8.00 | $20.0 |
| Cached input $/1M | $0.20 | $0.25 |
| Context window | 1M | 1M |
| Knowledge cutoff | 2026-06 | 2026-06 |
| License | proprietary | proprietary |
| Speed (tok/s) | 85 | 67 |
| Artificial Analysis Intelligence Index | 57.6 | 53.4 |
| LMArena Elo | — | 1508 |
| GPQA Diamond | — | 93.7% |
| Humanity's Last Exam | 61.4% | 59.1% |