Claude Fable 5.1 scores 69.4 on the Respan Index (#4), ahead of Qwen3.8-Flash-Next at 42.7 (#39). Claude Fable 5.1 leads on 8 of the 9 benchmarks both report.
* Estimated: no published scores in that category. How the Respan Index works
| LiveBench Language (LiveBench) | 89.5% | 74.6% |
| LiveBench Mathematics (LiveBench) | 97% | 85.8% |
| LiveBench Reasoning (LiveBench) | 91.7% | 87.4% |
| LMArena Agent (LMArena) | 0.1431 | -0.0073 |
| LMArena WebDev (LMArena) | 1749 | 1638 |
Higher is better. Each score links to where it was published.