Claude Fable 5.1 vs Gemini 3.8 Flash
Claude Fable 5.1 (Anthropic) and Gemini 3.8 Flash (Google) compared on price, context window, speed and independent benchmarks. Claude Fable 5.1 scores higher on the Artificial Analysis Intelligence Index (65.7 vs 58.7), while Gemini 3.8 Flash is 13.3× cheaper on a blended basis. Pick Claude Fable 5.1 for the hardest tasks and Gemini 3.8 Flash when cost dominates.
| Claude Fable 5.1 | Gemini 3.8 Flash | |
|---|---|---|
| Provider | Anthropic | |
| Input $/1M | $10.0 | $0.75 |
| Output $/1M | $50.0 | $3.75 |
| Blended $/1M (3:1) | $20.0 | $1.50 |
| Cached input $/1M | $0.25 | $0.07 |
| Context window | 1M | 1.0M |
| Knowledge cutoff | 2026-06 | — |
| License | proprietary | proprietary |
| Speed (tok/s) | 71 | 417 |
| Artificial Analysis Intelligence Index | 65.7 | 58.7 |
| GPQA Diamond | 93.7% | 95.3% |
| Humanity's Last Exam | 59.1% | 47.8% |