# 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.

- Canonical page: https://noometry.com/compare/claude-fable-5-1-vs-grok-3
- Last updated: 2026-10-12
- Shared benchmarks: 23

## 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.

## Snapshot

| | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 69.0 | 39.9 |
| Rank | 2 | 157 |
| Context | 1M | — |
| Input $/M | $10 | — |
| Output $/M | $50 | — |
| Weights | Proprietary | Proprietary |

## Coding

- 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: 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: 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: 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: 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

- 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: 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: 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: 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: 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% |

## FAQ

### 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.