Model comparison
Claude 3.5 Sonnet vs Claude Fable 5.1
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 34.6 on the Noometry Index.
Last verified . 25 shared benchmarks.
Summary
- They share 25 benchmarks with published results for both. Claude 3.5 Sonnet scores higher in 0 categories and Claude Fable 5.1 in 10 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 19.2.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 8.5% for Claude 3.5 Sonnet and 100% for Claude Fable 5.1.
Side by side
| Claude 3.5 Sonnet | Claude Fable 5.1 | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 34.6 | 69.0 |
| Released | 2024-06-20 | 2026-09-01 |
| Weights | Proprietary | Proprietary |
| Context window | — | 1M |
| Max output | — | 128K |
| Input $ / M tokens | — | $10 |
| Output $ / M tokens | — | $50 |
| Results tracked | 60 | 52 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Claude Fable 5.1 leads
Claude 3.5 Sonnet: 39.0 (#165), Claude Fable 5.1: 74.7 (#1)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| GSO | 4.6% | 88.2% |
| WeirdML | 40% | 92.9% |
| LMArena Coding | 1342 | 1528 |
| FrontierCode | — | 50.9% |
| Aider Polyglot | 51.6% | — |
| CursorBench | — | 51.8% |
| LMArena WebDev | — | 1744 |
| FrontierSWE | — | 56.3% |
| SciCode | — | 63.1% |
| BigCodeBench Instruct | 46.8% | — |
| LiveBench Coding | 67.1% | — |
| MirrorCode | — | 73.3% |
| BigCodeBench Complete | 58.6% | — |
| CadEval | 48% | — |
| ALE-Bench | — | 2,143 |
| HumanEval+ | 81.7% | — |
| MBPP+ | 74.3% | — |
Agentic & Tool Use Claude Fable 5.1 leads
Claude 3.5 Sonnet: 32.3 (#67), Claude Fable 5.1: 50.7 (#5)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| APEX-Agents | — | 68.6% |
| Remote Labor Index | — | 17.9% |
| TheAgentCompany | 24% | — |
| Cybench | 17.5% | — |
| BALROG | 32.6% | — |
| GDP.pdf | — | 29.6% |
| METR Time Horizons | 45.2% | — |
| Vending-Bench 2 | — | 5,422 |
Reasoning Claude Fable 5.1 leads
Claude 3.5 Sonnet: 23.1 (#183), Claude Fable 5.1: 76.7 (#7)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| LMArena Hard Prompts | 1305 | 1526 |
| DTBench | 67.8% | 97.6% |
| Epoch Capabilities Index | 133.55 | 164.7 |
| ARC-AGI-2 | — | 90% |
| SimpleBench | 41.4% | — |
| NYT Connections (extended) | — | 90% |
| ARC-AGI-1 | — | 97.5% |
| CritPt | — | 31.1% |
| Chess Puzzles | — | 47% |
| EnigmaEval | 0.9% | — |
| EBR-Bench | — | 57.1% |
| LiveBench Reasoning | 56.7% | — |
| Mystery Game Puzzles | — | 58% |
| LiveBench Data Analysis | 55% | — |
| LMCA | — | 65.5% |
| ForecastBench | 60.7 | — |
| LiveBench | 59% | — |
Math Claude Fable 5.1 leads
Claude 3.5 Sonnet: 19.2 (#288), Claude Fable 5.1: 89.6 (#4)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 8.5% | 100% |
| LMArena Math | 1307 | 1525 |
| FrontierMath (Tiers 1-3) | — | 90.2% |
| FrontierMath Tier 4 | — | 87.8% |
| ProofBench | — | 100% |
| Omni-MATH | 27.6% | — |
| LiveBench Math | 52.3% | — |
| MATH Level 5 | 56.9% | — |
| FrontierMath (Feb 2025 set) | 2.1% | — |
| FrontierMath Erdős | — | 0% |
| FrontierMath Tier 4 (v1) | 0% | — |
Knowledge Claude Fable 5.1 leads
Claude 3.5 Sonnet: 28.6 (#245), Claude Fable 5.1: 69.6 (#6)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| Humanity's Last Exam | 4.1% | 46.5% |
| LMArena Expert | 1265 | 1535 |
| GPQA Diamond | 55.3% | — |
| SimpleQA Verified | — | 70.8% |
| MMLU-Pro | 77.7% | — |
| Confabulations | 19.9% | — |
| GPQA (HELM) | 56.5% | — |
| MMLU | 87.3% | — |
Multimodal Claude Fable 5.1 leads
Claude 3.5 Sonnet: 26.5 (#120), Claude Fable 5.1: 53.9 (#4)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| LMArena Vision | 1125 | 1318 |
| Video-MME | 60% | — |
| GeoBench | 62% | — |
| VPCT | 33% | — |
| Blueprint-Bench 2 | — | 41.9% |
| Furniture Assembly | — | 70% |
| LMArena Document | — | 1513 |
Multilingual Claude Fable 5.1 leads
Claude 3.5 Sonnet: 43.2 (#185), Claude Fable 5.1: 59.1 (#3)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| LMArena Non-English | 1283 | 1507 |
| LMArena Chinese | 1272 | 1586 |
| LMArena French | 1305 | 1525 |
| LMArena German | 1297 | 1500 |
| LMArena Japanese | 1234 | 1543 |
| LMArena Korean | 1200 | 1534 |
| LMArena Russian | 1306 | 1521 |
| LMArena Spanish | 1290 | 1516 |
Instruction Following Claude Fable 5.1 leads
Claude 3.5 Sonnet: 68.8 (#182), Claude Fable 5.1: 79.2 (#6)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| LMArena Instruction Following | 1297 | 1517 |
| LiveBench Instruction Following | 69.3% | — |
| IFEval | 85.5% | — |
Long Context Claude Fable 5.1 leads
Claude 3.5 Sonnet: 39.9 (#167), Claude Fable 5.1: 46.7 (#20)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| LMArena Longer Query | 1311 | 1522 |
Writing & Preference Claude Fable 5.1 leads
Claude 3.5 Sonnet: 52.9 (#164), Claude Fable 5.1: 79.2 (#2)
| Benchmark | Claude 3.5 Sonnet | Claude Fable 5.1 |
|---|---|---|
| LMArena Text | 1298 | 1510 |
| LMArena Creative Writing | 1292 | 1507 |
| EQ-Bench Creative Writing | 1451 | 2162 |
| LMArena Multi-Turn | 1326 | 1492 |
| Short-Story Creative Writing | 80.3% | — |
| WildBench | 79.2% | — |
| LiveBench Language | 53.8% | — |
Frequently asked questions
Is Claude 3.5 Sonnet better than Claude Fable 5.1?
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 34.6 on the Noometry Index.
Is Claude 3.5 Sonnet or Claude Fable 5.1 better for coding?
Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 39.0 in the Noometry coding category.
How many benchmarks do Claude 3.5 Sonnet and Claude Fable 5.1 share?
25 benchmarks have published results for both models. Claude 3.5 Sonnet has 60 scored results on Noometry and Claude Fable 5.1 has 52.