Claude Fable 5.1 vs Mistral Medium 3.1
Claude Fable 5.1 leads Mistral Medium 3.1 on the Artificial Analysis Intelligence Index, 53.4 to 9.2, and Mistral Medium 3.1 costs 25.0x less per output token ($2.00 vs $50.00 per million). Updated October 22, 2026; 60 benchmarks have a result for both.
vs boards won of 60 shared
Claude Fable 5.1 or Mistral Medium 3.1: which to pick
Only Claude Fable 5.1 has a coding score, 84.2 on the Vibe Coding Index; Mistral Medium 3.1 has none, so the two cannot be ranked on coding.
Pick Mistral Medium 3.1 for output tokens 25.0x cheaper ($2.00 vs $50.00 per million).
Model AClaude Fable 5.1Anthropic84.2/1005 independent benchmarksNo cost per solved taskModel BMistral Medium 3.1Mistral AINot benchmarkedNo coding benchmarkNo cost per solved task
- Shared results
- 60
- Claude Fable 5.1 only
- 64
- Mistral Medium 3.1 only
- 14
- Like-for-like categories
- 8 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Only Claude Fable 5.1 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Claude Fable 5.1
Claude Fable 5.1 leads, 53.4 against 9.2.
Same board, both measured
Agentic work
AA Agentic Index
Claude Fable 5.1
Claude Fable 5.1 leads, 57.9 against 1.9.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only Claude Fable 5.1 has a GPQA Diamond result, 93.4%.
Directional only
Math
AIME
No call
Only Mistral Medium 3.1 has a AIME result, 42.3%.
Directional only
Knowledge
MMLU Pro
Claude Fable 5.1
Claude Fable 5.1 leads, 92.4% against 75.3%.
Same board, both measured
Web design
Design Arena: websites
Claude Fable 5.1
Claude Fable 5.1 leads, 1312 against 1132.
Same board, both measured
Long documents
Listed context window
Claude Fable 5.1
Claude Fable 5.1 takes 1M tokens against 131K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mistral Medium 3.1
Claude Fable 5.1 $0.035, Mistral Medium 3.1 $0.0014 per turn.
List prices
At a glance
- Coding index
- Claude Fable 5.1 84.2 from 5 benchmarks, Mistral Medium 3.1 not benchmarked.
- Widest category
- Agentic work, 56.0 points apart on average over 1 shared benchmark.
- Widest single gap
- ALE-Bench: Claude Fable 5.1 2143.2 against Mistral Medium 3.1 210.2, 64.4 points apart on a 0 to 100 scale.
- Output price
- Claude Fable 5.1 $50.00 against Mistral Medium 3.1 $2.00 per million output tokens, 25.0x apart.
- Context window
- Claude Fable 5.1 takes 1M tokens, Mistral Medium 3.1 131K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Claude Fable 5.1 | Bars | Mistral Medium 3.1 | Ties |
|---|---|---|---|---|
| Coding | 6 | 0 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 8 | 0 | ||
| Math | 2 | 0 | ||
| Knowledge | 8 | 0 | ||
| Web design | 8 | 0 | ||
| General | 26 | 0 | ||
| All shared boards | 60 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index60
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| LiveBench coding | 97.7% | Not measured | Only Claude Fable 5.1 measured |
| LMArena WebDev | 1743 | Not measured | Only Claude Fable 5.1 measured |
| AA Coding Index | 81.6 | 20.5 | Claude Fable 5.1 |
| LiveCodeBench (Vals AI) | 90.5% | 44.8% | Claude Fable 5.1 |
| Terminal-Bench 4 (Vals AI) | 58.1% | Not measured | Only Claude Fable 5.1 measured |
| Vibe Code Bench (Vals AI) | 90.3% | Not measured | Only Claude Fable 5.1 measured |
| Code migration (Vals AI) | 54.6% | Not measured | Only Claude Fable 5.1 measured |
| ProgramBench (Vals AI) | 7.0% | Not measured | Only Claude Fable 5.1 measured |
| IOI (Vals AI) | 90.8% | Not measured | Only Claude Fable 5.1 measured |
| Terminal-Bench 2.1 (Vals AI) | 85.0% | Not measured | Only Claude Fable 5.1 measured |
| SWE-bench Multimodal (Vals AI) | 61.3% | Not measured | Only Claude Fable 5.1 measured |
| Vibe Code Bench 1-100 (Vals AI) | 28.0% | Not measured | Only Claude Fable 5.1 measured |
| SkillsBench (Vals AI) | 61.5% | Not measured | Only Claude Fable 5.1 measured |
| CyberBench (Vals AI) | 70.4% | Not measured | Only Claude Fable 5.1 measured |
| LiveCodeBench (Artificial Analysis run) | Not measured | 40.6% | Only Mistral Medium 3.1 measured |
| SciCode | 63.1% | 32.4% | Claude Fable 5.1 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 10.6% | Only Mistral Medium 3.1 measured |
| FrontierCode | 50.9% | Not measured | Only Claude Fable 5.1 measured |
| FrontierSWE | 56.3% | Not measured | Only Claude Fable 5.1 measured |
| GSO-Bench | 88.2% | Not measured | Only Claude Fable 5.1 measured |
| WeirdML | 92.9% | Not measured | Only Claude Fable 5.1 measured |
| MirrorCode | 73.3% | Not measured | Only Claude Fable 5.1 measured |
| ALE-Bench | 2143.2 | 210.2 | Claude Fable 5.1 |
| LMArena Text: coding | 1532 | 1433 | Claude Fable 5.1 |
| LMArena Text: software and IT | 1530 | 1436 | Claude Fable 5.1 |
| LMArena WebDev: React | 1792 | Not measured | Only Claude Fable 5.1 measured |
| LMArena WebDev: HTML | 1684 | Not measured | Only Claude Fable 5.1 measured |
| LMArena WebDev: from an image | 1722 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 11 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| AA Intelligence Index | 53.4 | 9.2 | Claude Fable 5.1 |
| Epoch Capabilities Index | 166.5 | Not measured | Only Claude Fable 5.1 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| AA Agentic Index | 57.9 | 1.9 | Claude Fable 5.1 |
| Design Arena: agents building web apps | 1318 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building full-stack apps | 1326 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building mobile apps | 1267 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building Godot games | 1327 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: PowerPoint slides | 1305 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: spreadsheets | 1380 | Not measured | Only Claude Fable 5.1 measured |
| LiveBench research | 82.0% | Not measured | Only Claude Fable 5.1 measured |
| LiveBench browser | 100.0% | Not measured | Only Claude Fable 5.1 measured |
| LiveBench long agentic | 80.8% | Not measured | Only Claude Fable 5.1 measured |
| SREBench (Vals AI) | 22.9% | Not measured | Only Claude Fable 5.1 measured |
| Finance Agent (Vals AI) | 58.9% | Not measured | Only Claude Fable 5.1 measured |
| Tax Agent Bench (Vals AI) | 49.2% | Not measured | Only Claude Fable 5.1 measured |
| Legal Research Bench (Vals AI) | 55.3% | Not measured | Only Claude Fable 5.1 measured |
| Excel Modeling Benchmark (Vals AI) | 76.7% | Not measured | Only Claude Fable 5.1 measured |
| Terminal-Bench-Science (Vals AI) | 40.0% | Not measured | Only Claude Fable 5.1 measured |
| Time Horizon Index (Vals AI) | 63.3% | Not measured | Only Claude Fable 5.1 measured |
| CUA-bench (Vals AI) | 13.2% | Not measured | Only Claude Fable 5.1 measured |
| Robo-bench (Vals AI) | 5.8% | Not measured | Only Claude Fable 5.1 measured |
| τ²-Bench Telecom | Not measured | 40.6% | Only Mistral Medium 3.1 measured |
| APEX-Agents | 68.6% | Not measured | Only Claude Fable 5.1 measured |
| Remote Labor Index | 17.9% | Not measured | Only Claude Fable 5.1 measured |
| SpireClimb | 2.0% | Not measured | Only Claude Fable 5.1 measured |
| Vending-Bench 2 | $5,422 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Search | 1246 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 16 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| GPQA Diamond | 93.4% | Not measured | Only Claude Fable 5.1 measured |
| LiveBench reasoning | 91.7% | Not measured | Only Claude Fable 5.1 measured |
| MysteryMechanism (Vals AI) | 47.8% | Not measured | Only Claude Fable 5.1 measured |
| MMMU Pro (Vals AI) | 90.6% | 63.0% | Claude Fable 5.1 |
| GPQA Diamond (Artificial Analysis run) | 93.7% | 58.8% | Claude Fable 5.1 |
| Humanity's Last Exam (Artificial Analysis run) | 59.1% | 4.7% | Claude Fable 5.1 |
| ARC-AGI | 97.5% | Not measured | Only Claude Fable 5.1 measured |
| ARC-AGI-2 | 90.0% | Not measured | Only Claude Fable 5.1 measured |
| Chess puzzles | 48.0% | Not measured | Only Claude Fable 5.1 measured |
| Mystery game puzzles | 58.0% | Not measured | Only Claude Fable 5.1 measured |
| EBR-bench | 57.1% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: hard prompts | 1528 | 1426 | Claude Fable 5.1 |
| LMArena Text: expert | 1544 | 1408 | Claude Fable 5.1 |
| LMArena Text: hard prompts in English | 1522 | 1435 | Claude Fable 5.1 |
| LMArena Vision: diagrams | 1343 | 1175 | Claude Fable 5.1 |
| LMArena Vision: homework | 1345 | 1165 | Claude Fable 5.1 |
| Neither model has a result on the other 6 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| AIME | Not measured | 42.3% | Only Mistral Medium 3.1 measured |
| MATH 500 (Vals AI) | Not measured | 87.0% | Only Mistral Medium 3.1 measured |
| MGSM (Vals AI) | Not measured | 90.9% | Only Mistral Medium 3.1 measured |
| AA Math Index | Not measured | 38.3 | Only Mistral Medium 3.1 measured |
| AIME 2025 (Artificial Analysis run) | Not measured | 38.3% | Only Mistral Medium 3.1 measured |
| OTIS Mock AIME | 100.0% | Not measured | Only Claude Fable 5.1 measured |
| FrontierMath, tiers 1 to 3 | 90.2% | Not measured | Only Claude Fable 5.1 measured |
| FrontierMath, tier 4 | 87.8% | Not measured | Only Claude Fable 5.1 measured |
| ProofBench | 100.0% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: math | 1531 | 1408 | Claude Fable 5.1 |
| LMArena Text: mathematical work | 1541 | 1412 | Claude Fable 5.1 |
| Neither model has a result on the other 2 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| MMLU Pro | 92.4% | 75.3% | Claude Fable 5.1 |
| LegalBench (Vals AI) | 88.5% | 62.0% | Claude Fable 5.1 |
| CorpFin (Vals AI) | Not measured | 50.7% | Only Mistral Medium 3.1 measured |
| TaxEval (Vals AI) | 76.0% | 70.3% | Claude Fable 5.1 |
| MortgageTax (Vals AI) | 70.8% | 36.5% | Claude Fable 5.1 |
| MedQA (Vals AI) | Not measured | 78.2% | Only Mistral Medium 3.1 measured |
| MedCode (Vals AI) | 53.5% | Not measured | Only Claude Fable 5.1 measured |
| MMLU Pro (Artificial Analysis run) | Not measured | 68.3% | Only Mistral Medium 3.1 measured |
| SimpleQA Verified | 70.8% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: science | 1532 | 1444 | Claude Fable 5.1 |
| LMArena Text: medicine and healthcare | 1531 | 1449 | Claude Fable 5.1 |
| LMArena Text: legal and government | 1514 | 1439 | Claude Fable 5.1 |
| LMArena Text: business and finance | 1493 | 1418 | Claude Fable 5.1 |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| Design Arena: websites | 1312 | 1132 | Claude Fable 5.1 |
| Design Arena: UI components | 1336 | 1097 | Claude Fable 5.1 |
| Design Arena: game dev | 1381 | 1073 | Claude Fable 5.1 |
| Design Arena: data viz | 1344 | 1144 | Claude Fable 5.1 |
| Design Arena: 3D | 1392 | 1081 | Claude Fable 5.1 |
| Design Arena: all code categories | 1335 | 1120 | Claude Fable 5.1 |
| Design Arena: SVG | 1300 | 992 | Claude Fable 5.1 |
| Design Arena: ASCII art | 1323 | 997 | Claude Fable 5.1 |
| LiveBench design | 83.4% | Not measured | Only Claude Fable 5.1 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index260
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| LiveBench data analysis | 80.3% | Not measured | Only Claude Fable 5.1 measured |
| Public Benefits Bench (Vals AI) | 74.9% | Not measured | Only Claude Fable 5.1 measured |
| SAGE (Vals AI) | 48.5% | Not measured | Only Claude Fable 5.1 measured |
| MedScribe (Vals AI) | 91.3% | Not measured | Only Claude Fable 5.1 measured |
| IFBench | Not measured | 39.8% | Only Mistral Medium 3.1 measured |
| Long context reasoning (AA-LCR) | 85.3% | 42.7% | Claude Fable 5.1 |
| DTBench | 97.6% | 67.5% | Claude Fable 5.1 |
| LMCA | 65.5% | 19.1% | Claude Fable 5.1 |
| Furniture assembly | 70.0% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text | 1512 | 1424 | Claude Fable 5.1 |
| LMArena Text: instruction following | 1518 | 1398 | Claude Fable 5.1 |
| LMArena Text: creative writing | 1509 | 1391 | Claude Fable 5.1 |
| LMArena Vision | 1319 | 1172 | Claude Fable 5.1 |
| LMArena Text: English | 1506 | 1438 | Claude Fable 5.1 |
| LMArena Text: non-English | 1508 | 1408 | Claude Fable 5.1 |
| LMArena Text: Chinese | 1584 | 1447 | Claude Fable 5.1 |
| LMArena Text: German | 1499 | 1432 | Claude Fable 5.1 |
| LMArena Text: Japanese | 1562 | 1379 | Claude Fable 5.1 |
| LMArena Text: Korean | 1517 | 1380 | Claude Fable 5.1 |
| LMArena Text: French | 1523 | 1460 | Claude Fable 5.1 |
| LMArena Text: Spanish | 1520 | 1433 | Claude Fable 5.1 |
| LMArena Text: Russian | 1520 | 1411 | Claude Fable 5.1 |
| LMArena Text: Polish | 1525 | 1430 | Claude Fable 5.1 |
| LMArena Text: multi-turn | 1493 | 1418 | Claude Fable 5.1 |
| LMArena Text: longer queries | 1524 | 1406 | Claude Fable 5.1 |
| LMArena Text: writing and language | 1510 | 1395 | Claude Fable 5.1 |
| LMArena Text: entertainment and media | 1497 | 1390 | Claude Fable 5.1 |
| LMArena Vision: English | 1313 | 1179 | Claude Fable 5.1 |
| LMArena Vision: Chinese | 1391 | 1190 | Claude Fable 5.1 |
| LMArena Vision: reading text | 1327 | 1175 | Claude Fable 5.1 |
| LMArena Vision: humor | 1318 | 1168 | Claude Fable 5.1 |
| LMArena Vision: captioning | Not measured | 1145 | Only Mistral Medium 3.1 measured |
| LMArena Vision: recognizing things | Not measured | 1147 | Only Mistral Medium 3.1 measured |
| LMArena Vision: creative writing | 1330 | 1200 | Claude Fable 5.1 |
| Neither model has a result on the other 12 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Fable 5.1 | Mistral Medium 3.1 | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Claude Fable 5.1$0.035Fits in one request
Mistral Medium 3.1$0.0014Fits in one request
Mistral Medium 3.1 costs less
Repository review
50K input + 3K output tokens
Claude Fable 5.1$0.650Fits in one request
Mistral Medium 3.1$0.026Fits in one request
Mistral Medium 3.1 costs less
Agent loop
200K input + 10K output tokens
Claude Fable 5.1$2.50Fits in one request
Mistral Medium 3.1$0.100Exceeds the context window
Mistral Medium 3.1 costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Anthropic Claude Fable 5.1 | Mistral Medium 3.1 |
|---|---|---|
| Maker | Anthropic | Mistral AI |
| Weights | No public weights listed | No public weights listed |
| Released | September 1, 2026 | August 13, 2025 |
| Context window | 1M | 131K |
| Input $/Mtok | $10.00 | $0.40 |
| Output $/Mtok | $50.00 | $2.00 |
| Coding index | 84.2 | Not benchmarked |
| Independent measurements behind it | 5 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Fable 5.1 better than Mistral Medium 3.1 for coding?
Only Claude Fable 5.1 has a coding score, 84.2 on the Vibe Coding Index; Mistral Medium 3.1 has none, so the two cannot be ranked on coding. Pick Mistral Medium 3.1 for output tokens 25.0x cheaper ($2.00 vs $50.00 per million).
Which is cheaper, Claude Fable 5.1 or Mistral Medium 3.1?
Claude Fable 5.1 costs $10.00 per million input tokens and $50.00 per million output tokens; Mistral Medium 3.1 costs $0.40 and $2.00. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Fable 5.1 or Mistral Medium 3.1?
Claude Fable 5.1, with 1M tokens against 131K.
How many benchmarks is the Claude Fable 5.1 vs Mistral Medium 3.1 comparison based on?
60 benchmarks have a result for both models as of October 22, 2026. Claude Fable 5.1's coding index rests on 5 independent benchmarks and Mistral Medium 3.1's on 0. Where only one model has a result, the page says so instead of naming a winner.