Claude Fable 5.1 vs Qwen3.5 Plus 2026-04-20
Claude Fable 5.1 
Qwen3.5 Plus 2026-04-20 Verdict
- Claude Fable 5.1 (max) leads on quality: 70.1 vs 57.3.
- Claude Fable 5.1 (max) is stronger in agents & tools, coding, composite, human preference, knowledge, maths, reasoning.
- Qwen3.5 Plus 2026-04-20 (thinking) is 16× cheaper ($1.29 vs $20.00 per 1M blended).
| Metric | Claude Fable 5.1 (max) | Qwen3.5 Plus 2026-04-20 (thinking) |
|---|---|---|
| BenchLeader Index | 70.1 | 57.3 |
| Agents & tools score | 67.2 | – |
| Coding score | 78.1 | 61.8 |
| Composite score | 76.6 | – |
| Human preference score | 70.8 | – |
| Knowledge score | 75.9 | 60.5 |
| Maths score | 77.0 | 60.6 |
| Reasoning score | 71.8 | – |
| Blended price $/M | $20.00 | $1.29 |
| Output speed | 67 tok/s | 52 tok/s |
| Time to first answer | 258.6 s | 0.9 s |
| Context window | 1M | 1M |
| FrontierMath Tiers 1–3 | 90.2% | – |
| FrontierMath Tier 4 | 87.8% | – |
| OTIS Mock AIME | 100.0% | – |
| SimpleQA Verified | 70.8% | – |
| Terminal-Bench | 57.9% | – |
| SciCode | 62.0% | – |
| WeirdML | 92.9% | – |
| ProofBench | 100.0% | – |
| LMArena Text | 1501 | – |
| LMArena Hard Prompts | 1519 | – |
| LMArena Coding | 1519 | – |
| LMArena WebDev | 1758 | – |
| LMArena Agent | 13.9 | – |
| LiveBench | 83.4% | – |
| LiveBench Reasoning | 91.7% | – |
| LiveBench Coding | 86.4% | – |
| LiveBench Agentic Coding | 66.1% | – |
| LiveBench Mathematics | 97.0% | – |
| LiveBench Data Analysis | 80.3% | – |
| LiveBench Language | 89.5% | – |
| AIME (Vals) | – | 86.0% |
| LiveCodeBench | – | 85.3% |
| MMLU-Pro | – | 87.2% |
| LegalBench | – | 85.1% |
| CorpFin | – | 65.3% |
| MedQA | – | 95.2% |
| SWE-bench (Vals) | – | 71.2% |
| GPQA Diamond (Vals) | – | 87.4% |
| ARC-AGI-1 | 97.5% | – |
| ARC-AGI-2 | 90.0% | – |
Data as of 2026-09-13. Best configuration of each model; every score links to its source on the model pages.
Claude Fable 5.1 vs Qwen3.5 Plus 2026-04-20: questions
- Is Claude Fable 5.1 better than Qwen3.5 Plus 2026-04-20?
- Claude Fable 5.1 (max) leads on quality: 70.1 vs 57.3. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5.1 (max) is ahead overall as of 2026-09-13, but check the category scores for your use.
- Is Claude Fable 5.1 better than Qwen3.5 Plus 2026-04-20 for coding?
- Claude Fable 5.1 scores higher in coding (78 vs 62 on the category index, where 50 is average).
- Which is cheaper, Claude Fable 5.1 or Qwen3.5 Plus 2026-04-20?
- Qwen3.5 Plus 2026-04-20 is cheaper: $1.29 against $20.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Fable 5.1 or Qwen3.5 Plus 2026-04-20?
- Claude Fable 5.1 streams faster: 67 against 52 output tokens per second.
- Which has the larger context window?
- Both accept 1M tokens of context.