Model comparison
Claude Fable 5.1 vs Grok 3
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 39.9 on the Noometry Index.
Last verified . 23 shared benchmarks.
Summary
- They share 23 benchmarks with published results for both. Claude Fable 5.1 scores higher in 9 categories and Grok 3 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Fable 5.1 leads 76.7 to 13.7.
- The biggest single-benchmark swing is ARC-AGI-1: 97.5% for Claude Fable 5.1 and 5.5% for Grok 3.
Side by side
| Claude Fable 5.1 | Grok 3 | |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 69.0 | 39.9 |
| Released | 2026-09-01 | 2025-04-09 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $10 | — |
| Output $ / M tokens | $50 | — |
| Results tracked | 52 | 40 |
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Category by category
Coding Claude Fable 5.1 leads
Claude Fable 5.1: 74.7 (#1), Grok 3: 41.9 (#115)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| WeirdML | 92.9% | 37.2% |
| LMArena Coding | 1528 | 1432 |
| FrontierCode | 50.9% | — |
| Aider Polyglot | — | 53.3% |
| 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), Grok 3: 30.5 (#76)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| APEX-Agents | 68.6% | — |
| Remote Labor Index | 17.9% | — |
| BALROG | — | 29.5% |
| GDP.pdf | 29.6% | — |
| Vending-Bench 2 | 5,422 | — |
Reasoning Claude Fable 5.1 leads
Claude Fable 5.1: 76.7 (#7), Grok 3: 13.7 (#333)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| ARC-AGI-2 | 90% | 0% |
| ARC-AGI-1 | 97.5% | 5.5% |
| LMArena Hard Prompts | 1526 | 1434 |
| Epoch Capabilities Index | 164.7 | 138.33 |
| SimpleBench | — | 36.1% |
| Kagi LLM Benchmark | — | 61.3% |
| NYT Connections (extended) | 90% | — |
| CritPt | 31.1% | — |
| Chess Puzzles | 47% | — |
| 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), Grok 3: 38.0 (#145)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 55.6% |
| LMArena Math | 1525 | 1391 |
| FrontierMath (Tiers 1-3) | 90.2% | — |
| FrontierMath Tier 4 | 87.8% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 46.4% |
| MATH Level 5 | — | 88.7% |
| FrontierMath (Feb 2025 set) | — | 3.8% |
| FrontierMath Erdős | 0% | — |
| FrontierMath Tier 4 (v1) | — | 0% |
Knowledge Claude Fable 5.1 leads
Claude Fable 5.1: 69.6 (#6), Grok 3: 46.2 (#82)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| LMArena Expert | 1535 | 1421 |
| GPQA Diamond | — | 75.8% |
| Humanity's Last Exam | 46.5% | — |
| SimpleQA Verified | 70.8% | — |
| MMLU-Pro | — | 78.8% |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 5.8% |
| GPQA (HELM) | — | 65% |
Multimodal Not comparable
Claude Fable 5.1: 53.9 (#4), Grok 3: —
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| 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), Grok 3: 52.3 (#87)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| LMArena Non-English | 1507 | 1410 |
| LMArena Chinese | 1586 | 1448 |
| LMArena French | 1525 | 1460 |
| LMArena German | 1500 | 1431 |
| LMArena Japanese | 1543 | 1387 |
| LMArena Korean | 1534 | 1373 |
| LMArena Russian | 1521 | 1416 |
| LMArena Spanish | 1516 | 1417 |
Instruction Following Claude Fable 5.1 leads
Claude Fable 5.1: 79.2 (#6), Grok 3: 75.0 (#73)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| LMArena Instruction Following | 1517 | 1409 |
| IFEval | — | 88.4% |
Long Context Claude Fable 5.1 leads
Claude Fable 5.1: 46.7 (#20), Grok 3: 38.7 (#192)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| LMArena Longer Query | 1522 | 1439 |
| Fiction.LiveBench | — | 58.3% |
Writing & Preference Claude Fable 5.1 leads
Claude Fable 5.1: 79.2 (#2), Grok 3: 55.8 (#141)
| Benchmark | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| LMArena Text | 1510 | 1426 |
| LMArena Creative Writing | 1507 | 1414 |
| EQ-Bench Creative Writing | 2162 | 1186 |
| LMArena Multi-Turn | 1492 | 1425 |
| Short-Story Creative Writing | — | 76.4% |
| WildBench | — | 84.9% |
Frequently asked questions
Is Claude Fable 5.1 better than Grok 3?
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 39.9 on the Noometry Index.
Is Claude Fable 5.1 or Grok 3 better for coding?
Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 41.9 in the Noometry coding category.
How many benchmarks do Claude Fable 5.1 and Grok 3 share?
23 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Grok 3 has 40.