# Claude 2 vs Claude Fable 5.1

> Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 25.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-vs-claude-fable-5-1
- Last updated: 2026-10-10
- Shared benchmarks: 3

## Summary

- They share 3 benchmarks with published results for both. Claude 2 scores higher in 0 categories and Claude Fable 5.1 in 3 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 9.3.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 2.5% for Claude 2 and 100% for Claude Fable 5.1.

## Snapshot

| | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 25.0 | 69.0 |
| Rank | 346 | 2 |
| Context | — | 1M |
| Input $/M | — | $10 |
| Output $/M | — | $50 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2: —
- Claude Fable 5.1: 74.7 (#1)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| FrontierCode | — | 50.9% |
| CursorBench | — | 51.8% |
| LMArena WebDev | — | 1744 |
| FrontierSWE | — | 56.3% |
| SciCode | — | 63.1% |
| GSO | — | 88.2% |
| WeirdML | — | 92.9% |
| LMArena Coding | — | 1528 |
| MirrorCode | — | 73.3% |
| ALE-Bench | — | 2,143 |
| HumanEval+ | 61.6% | — |

## Agentic & Tool Use

- Claude 2: —
- Claude Fable 5.1: 50.7 (#5)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| APEX-Agents | — | 68.6% |
| Remote Labor Index | — | 17.9% |
| GDP.pdf | — | 29.6% |
| Vending-Bench 2 | — | 5,422 |

## Reasoning

- Claude 2: 21.7 (#216)
- Claude Fable 5.1: 76.7 (#7)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| DTBench | 51.9% | 97.6% |
| Epoch Capabilities Index | 120.13 | 164.7 |
| ARC-AGI-2 | — | 90% |
| NYT Connections (extended) | — | 90% |
| ARC-AGI-1 | — | 97.5% |
| CritPt | — | 31.1% |
| Chess Puzzles | — | 47% |
| EBR-Bench | — | 57.1% |
| LMArena Hard Prompts | — | 1526 |
| Mystery Game Puzzles | — | 58% |
| LMCA | — | 65.5% |

## Math

- Claude 2: 9.3 (#320)
- Claude Fable 5.1: 89.6 (#4)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 2.5% | 100% |
| FrontierMath (Tiers 1-3) | — | 90.2% |
| FrontierMath Tier 4 | — | 87.8% |
| ProofBench | — | 100% |
| LMArena Math | — | 1525 |
| MATH Level 5 | 11.7% | — |
| FrontierMath Erdős | — | 0% |

## Knowledge

- Claude 2: 16.9 (#287)
- Claude Fable 5.1: 69.6 (#6)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| GPQA Diamond | 34.7% | — |
| Humanity's Last Exam | — | 46.5% |
| SimpleQA Verified | — | 70.8% |
| LMArena Expert | — | 1535 |
| MMLU | 78.5% | — |
| TriviaQA | 87.5% | — |

## Multimodal

- Claude 2: —
- Claude Fable 5.1: 53.9 (#4)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| LMArena Vision | — | 1318 |
| Blueprint-Bench 2 | — | 41.9% |
| Furniture Assembly | — | 70% |
| LMArena Document | — | 1513 |

## Multilingual

- Claude 2: —
- Claude Fable 5.1: 59.1 (#3)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| LMArena Non-English | — | 1507 |
| LMArena Chinese | — | 1586 |
| LMArena French | — | 1525 |
| LMArena German | — | 1500 |
| LMArena Japanese | — | 1543 |
| LMArena Korean | — | 1534 |
| LMArena Russian | — | 1521 |
| LMArena Spanish | — | 1516 |

## Instruction Following

- Claude 2: —
- Claude Fable 5.1: 79.2 (#6)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| LMArena Instruction Following | — | 1517 |

## Long Context

- Claude 2: —
- Claude Fable 5.1: 46.7 (#20)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| LMArena Longer Query | — | 1522 |

## Writing & Preference

- Claude 2: —
- Claude Fable 5.1: 79.2 (#2)

| Benchmark | Claude 2 | Claude Fable 5.1 |
|---|---|---|
| LMArena Text | — | 1510 |
| LMArena Creative Writing | — | 1507 |
| EQ-Bench Creative Writing | — | 2162 |
| LMArena Multi-Turn | — | 1492 |

## FAQ

### Is Claude 2 better than Claude Fable 5.1?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 25.0 on the Noometry Index.

### How many benchmarks do Claude 2 and Claude Fable 5.1 share?

3 benchmarks have published results for both models. Claude 2 has 8 scored results on Noometry and Claude Fable 5.1 has 52.