Model comparison
Claude Fable 5.1 vs Mistral Small 3.1
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 50× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.
Last verified . 22 shared benchmarks.
Mistral AISummary
- They share 22 benchmarks with published results for both. Claude Fable 5.1 scores higher in 9 categories and Mistral Small 3.1 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 14.7.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Fable 5.1 and 3.9% for Mistral Small 3.1.
- Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
- Claude Fable 5.1 accepts more context: 1M tokens versus 128K.
- Mistral Small 3.1 has downloadable open weights; the other is API-only.
Side by side
| Claude Fable 5.1 | Mistral Small 3.1 | |
|---|---|---|
| Provider | Anthropic | Mistral AI |
| Noometry Index | 69.0 | 31.7 |
| Released | 2026-09-01 | 2025-03-17 |
| Weights | Proprietary | Open |
| Context window | 1M | 128K |
| Max output | 128K | 102K |
| Input $ / M tokens | $10 | $0.35 |
| Output $ / M tokens | $50 | $0.56 |
| Results tracked | 52 | 28 |
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Category by category
Coding Claude Fable 5.1 leads
Claude Fable 5.1: 74.7 (#1), Mistral Small 3.1: 38.3 (#179)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Coding | 1528 | 1309 |
| FrontierCode | 50.9% | — |
| CursorBench | 51.8% | — |
| LMArena WebDev | 1744 | — |
| FrontierSWE | 56.3% | — |
| SciCode | 63.1% | — |
| GSO | 88.2% | — |
| WeirdML | 92.9% | — |
| MirrorCode | 73.3% | — |
| ALE-Bench | 2,143 | — |
Agentic & Tool Use Not comparable
Claude Fable 5.1: 50.7 (#5), Mistral Small 3.1: —
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| APEX-Agents | 68.6% | — |
| Remote Labor Index | 17.9% | — |
| GDP.pdf | 29.6% | — |
| Vending-Bench 2 | 5,422 | — |
Reasoning Claude Fable 5.1 leads
Claude Fable 5.1: 76.7 (#7), Mistral Small 3.1: 19.7 (#254)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| Chess Puzzles | 47% | 1% |
| LMArena Hard Prompts | 1526 | 1278 |
| Epoch Capabilities Index | 164.7 | 127.48 |
| ARC-AGI-2 | 90% | — |
| NYT Connections (extended) | 90% | — |
| ARC-AGI-1 | 97.5% | — |
| CritPt | 31.1% | — |
| EBR-Bench | 57.1% | — |
| Mystery Game Puzzles | 58% | — |
| DTBench | 97.6% | — |
| LMCA | 65.5% | — |
Math Claude Fable 5.1 leads
Claude Fable 5.1: 89.6 (#4), Mistral Small 3.1: 14.7 (#301)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 3.9% |
| LMArena Math | 1525 | 1262 |
| FrontierMath (Tiers 1-3) | 90.2% | — |
| FrontierMath Tier 4 | 87.8% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 24.8% |
| FrontierMath Erdős | 0% | — |
Knowledge Claude Fable 5.1 leads
Claude Fable 5.1: 69.6 (#6), Mistral Small 3.1: 22.6 (#271)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Expert | 1535 | 1257 |
| GPQA Diamond | — | 41.9% |
| Humanity's Last Exam | 46.5% | — |
| SimpleQA Verified | 70.8% | — |
| MMLU-Pro | — | 61% |
| GPQA (HELM) | — | 39.2% |
Multimodal Claude Fable 5.1 leads
Claude Fable 5.1: 53.9 (#4), Mistral Small 3.1: 33.2 (#99)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | 1318 | 1136 |
| Blueprint-Bench 2 | 41.9% | — |
| Furniture Assembly | 70% | — |
| LMArena Document | 1513 | — |
Multilingual Claude Fable 5.1 leads
Claude Fable 5.1: 59.1 (#3), Mistral Small 3.1: 41.2 (#209)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | 1507 | 1255 |
| LMArena Chinese | 1586 | 1253 |
| LMArena French | 1525 | 1273 |
| LMArena German | 1500 | 1266 |
| LMArena Japanese | 1543 | 1208 |
| LMArena Korean | 1534 | 1206 |
| LMArena Russian | 1521 | 1263 |
| LMArena Spanish | 1516 | 1283 |
Instruction Following Claude Fable 5.1 leads
Claude Fable 5.1: 79.2 (#6), Mistral Small 3.1: 63.6 (#230)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Instruction Following | 1517 | 1264 |
| IFEval | — | 75% |
Long Context Claude Fable 5.1 leads
Claude Fable 5.1: 46.7 (#20), Mistral Small 3.1: 39.5 (#178)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | 1522 | 1299 |
Writing & Preference Claude Fable 5.1 leads
Claude Fable 5.1: 79.2 (#2), Mistral Small 3.1: 37.0 (#259)
| Benchmark | Claude Fable 5.1 | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | 1510 | 1277 |
| LMArena Creative Writing | 1507 | 1253 |
| EQ-Bench Creative Writing | 2162 | 761 |
| LMArena Multi-Turn | 1492 | 1270 |
| WildBench | — | 78.8% |
Frequently asked questions
Is Claude Fable 5.1 better than Mistral Small 3.1?
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 50× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.
Which is cheaper, Claude Fable 5.1 or Mistral Small 3.1?
Mistral Small 3.1 is cheaper. It lists at $0.35 per million input tokens and $0.56 per million output tokens; Claude Fable 5.1 lists at $10 and $50.
Is Claude Fable 5.1 or Mistral Small 3.1 better for coding?
Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 38.3 in the Noometry coding category.
Which has the bigger context window?
Claude Fable 5.1 does, with 1M tokens against 128K.
How many benchmarks do Claude Fable 5.1 and Mistral Small 3.1 share?
22 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Mistral Small 3.1 has 28.