Model comparison
Claude Fable 5.1 vs Llama 3.1-405B
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 30.7 on the Noometry Index.
Last verified . 22 shared benchmarks.
MetaSummary
- They share 22 benchmarks with published results for both. Claude Fable 5.1 scores higher in 9 categories and Llama 3.1-405B 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 18.4.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Fable 5.1 and 9.7% for Llama 3.1-405B.
- Llama 3.1-405B has downloadable open weights; the other is API-only.
Side by side
| Claude Fable 5.1 | Llama 3.1-405B | |
|---|---|---|
| Provider | Anthropic | Meta |
| Noometry Index | 69.0 | 30.7 |
| Released | 2026-09-01 | 2024-07-23 |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $10 | — |
| Output $ / M tokens | $50 | — |
| Results tracked | 52 | 42 |
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Category by category
Coding Claude Fable 5.1 leads
Claude Fable 5.1: 74.7 (#1), Llama 3.1-405B: 33.1 (#262)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| WeirdML | 92.9% | 21.4% |
| LMArena Coding | 1528 | 1291 |
| FrontierCode | 50.9% | — |
| CursorBench | 51.8% | — |
| LMArena WebDev | 1744 | — |
| FrontierSWE | 56.3% | — |
| SciCode | 63.1% | — |
| GSO | 88.2% | — |
| MirrorCode | 73.3% | — |
| ALE-Bench | 2,143 | — |
Agentic & Tool Use Claude Fable 5.1 leads
Claude Fable 5.1: 50.7 (#5), Llama 3.1-405B: 21.0 (#140)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| APEX-Agents | 68.6% | — |
| Remote Labor Index | 17.9% | — |
| TheAgentCompany | — | 7.4% |
| Cybench | — | 7.5% |
| GDP.pdf | 29.6% | — |
| Vending-Bench 2 | 5,422 | — |
Reasoning Claude Fable 5.1 leads
Claude Fable 5.1: 76.7 (#7), Llama 3.1-405B: 16.8 (#300)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Hard Prompts | 1526 | 1269 |
| DTBench | 97.6% | 61.4% |
| Epoch Capabilities Index | 164.7 | 128.75 |
| ARC-AGI-2 | 90% | — |
| SimpleBench | — | 23% |
| Kagi LLM Benchmark | — | 45% |
| NYT Connections (extended) | 90% | — |
| ARC-AGI-1 | 97.5% | — |
| CritPt | 31.1% | — |
| Chess Puzzles | 47% | — |
| EBR-Bench | 57.1% | — |
| Mystery Game Puzzles | 58% | — |
| LMCA | 65.5% | — |
| BIG-Bench Hard | — | 82.9% |
| ForecastBench | — | 59.9 |
| HellaSwag | — | 89.2% |
| PIQA | — | 85.9% |
| WinoGrande | — | 89.2% |
Math Claude Fable 5.1 leads
Claude Fable 5.1: 89.6 (#4), Llama 3.1-405B: 18.4 (#290)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 9.7% |
| LMArena Math | 1525 | 1281 |
| FrontierMath (Tiers 1-3) | 90.2% | — |
| FrontierMath Tier 4 | 87.8% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 24.9% |
| MATH Level 5 | — | 49.8% |
| FrontierMath Erdős | 0% | — |
Knowledge Claude Fable 5.1 leads
Claude Fable 5.1: 69.6 (#6), Llama 3.1-405B: 30.4 (#227)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Expert | 1535 | 1243 |
| GPQA Diamond | — | 50.9% |
| Humanity's Last Exam | 46.5% | — |
| SimpleQA Verified | 70.8% | — |
| MMLU-Pro | — | 72.3% |
| Confabulations | — | 17.6% |
| GPQA (HELM) | — | 52.2% |
| ARC (AI2) Challenge | — | 95.3% |
| MMLU | — | 84.5% |
| TriviaQA | — | 82.7% |
Multimodal Not comparable
Claude Fable 5.1: 53.9 (#4), Llama 3.1-405B: —
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Vision | 1318 | — |
| Blueprint-Bench 2 | 41.9% | — |
| Furniture Assembly | 70% | — |
| LMArena Document | 1513 | — |
Multilingual Claude Fable 5.1 leads
Claude Fable 5.1: 59.1 (#3), Llama 3.1-405B: 40.7 (#214)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Non-English | 1507 | 1248 |
| LMArena Chinese | 1586 | 1242 |
| LMArena French | 1525 | 1279 |
| LMArena German | 1500 | 1252 |
| LMArena Japanese | 1543 | 1208 |
| LMArena Korean | 1534 | 1184 |
| LMArena Russian | 1521 | 1265 |
| LMArena Spanish | 1516 | 1260 |
Instruction Following Claude Fable 5.1 leads
Claude Fable 5.1: 79.2 (#6), Llama 3.1-405B: 65.9 (#214)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Instruction Following | 1517 | 1259 |
| IFEval | — | 81.1% |
Long Context Claude Fable 5.1 leads
Claude Fable 5.1: 46.7 (#20), Llama 3.1-405B: 38.4 (#197)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Longer Query | 1522 | 1266 |
Writing & Preference Claude Fable 5.1 leads
Claude Fable 5.1: 79.2 (#2), Llama 3.1-405B: 38.9 (#251)
| Benchmark | Claude Fable 5.1 | Llama 3.1-405B |
|---|---|---|
| LMArena Text | 1510 | 1284 |
| LMArena Creative Writing | 1507 | 1262 |
| EQ-Bench Creative Writing | 2162 | 870 |
| LMArena Multi-Turn | 1492 | 1297 |
| WildBench | — | 78.3% |
Frequently asked questions
Is Claude Fable 5.1 better than Llama 3.1-405B?
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 30.7 on the Noometry Index.
Is Claude Fable 5.1 or Llama 3.1-405B better for coding?
Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 33.1 in the Noometry coding category.
How many benchmarks do Claude Fable 5.1 and Llama 3.1-405B share?
22 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Llama 3.1-405B has 42.