# Claude Fable 5.1 vs GPT-4o

> Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 28.6 on the Noometry Index. GPT-4o costs 4.6× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-fable-5-1-vs-gpt-4o
- Last updated: 2026-10-10
- Shared benchmarks: 31

## Summary

- They share 31 benchmarks with published results for both. Claude Fable 5.1 scores higher in 10 categories and GPT-4o in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 10.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Fable 5.1 and 6.4% for GPT-4o.
- GPT-4o is cheaper at $2.50 / $10 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
- Claude Fable 5.1 accepts more context: 1M tokens versus 128K.

## Snapshot

| | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 69.0 | 28.6 |
| Rank | 2 | 324 |
| Context | 1M | 128K |
| Input $/M | $10 | $2.50 |
| Output $/M | $50 | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Fable 5.1: 74.7 (#1)
- GPT-4o: 24.8 (#328)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| GSO | 88.2% | 0% |
| WeirdML | 92.9% | 25.1% |
| LMArena Coding | 1528 | 1297 |
| SWE-bench Verified | — | 31% |
| FrontierCode | 50.9% | — |
| SWE-bench Verified (bash only) | — | 21.6% |
| Aider Polyglot | — | 45.3% |
| CursorBench | 51.8% | — |
| LMArena WebDev | 1744 | — |
| FrontierSWE | 56.3% | — |
| SciCode | 63.1% | — |
| BigCodeBench Instruct | — | 51.1% |
| LiveBench Coding | — | 51.4% |
| MirrorCode | 73.3% | — |
| BigCodeBench Complete | — | 61.1% |
| CadEval | — | 26% |
| ALE-Bench | 2,143 | — |
| HumanEval+ | — | 87.2% |
| MBPP+ | — | 72.2% |

## Agentic & Tool Use

- Claude Fable 5.1: 50.7 (#5)
- GPT-4o: 21.0 (#141)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| APEX-Agents | 68.6% | — |
| GDPval | — | 9.9% |
| Remote Labor Index | 17.9% | — |
| TheAgentCompany | — | 8.6% |
| Cybench | — | 12.5% |
| BALROG | — | 32.3% |
| GDP.pdf | 29.6% | — |
| LMArena Search | — | 1006 |
| METR Time Horizons | — | 40.8% |
| Vending-Bench 2 | 5,422 | — |

## Reasoning

- Claude Fable 5.1: 76.7 (#7)
- GPT-4o: 9.4 (#343)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| ARC-AGI-2 | 90% | 0% |
| ARC-AGI-1 | 97.5% | 4.5% |
| CritPt | 31.1% | 0% |
| Chess Puzzles | 47% | 13% |
| LMArena Hard Prompts | 1526 | 1281 |
| DTBench | 97.6% | 64.5% |
| LMCA | 65.5% | 16.6% |
| Epoch Capabilities Index | 164.7 | 128.97 |
| SimpleBench | — | 17.8% |
| NYT Connections (extended) | 90% | — |
| EnigmaEval | — | 0.8% |
| EBR-Bench | 57.1% | — |
| LiveBench Reasoning | — | 55.8% |
| Mystery Game Puzzles | 58% | — |
| LiveBench Data Analysis | — | 60.9% |
| ForecastBench | — | 57.7 |
| LiveBench | — | 55.3% |

## Math

- Claude Fable 5.1: 89.6 (#4)
- GPT-4o: 10.6 (#312)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| FrontierMath (Tiers 1-3) | 90.2% | 0.4% |
| OTIS Mock AIME 2024-2025 | 100% | 6.4% |
| LMArena Math | 1525 | 1285 |
| FrontierMath Tier 4 | 87.8% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 29.3% |
| LiveBench Math | — | 49.5% |
| MATH Level 5 | — | 53.3% |
| FrontierMath (Feb 2025 set) | — | 0.3% |
| FrontierMath Erdős | 0% | — |

## Knowledge

- Claude Fable 5.1: 69.6 (#6)
- GPT-4o: 28.8 (#242)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| Humanity's Last Exam | 46.5% | 2.7% |
| SimpleQA Verified | 70.8% | 26% |
| LMArena Expert | 1535 | 1250 |
| GPQA Diamond | — | 49.2% |
| MMLU-Pro | — | 71.3% |
| Confabulations | — | 15.3% |
| Vectara Hallucination Rate | — | 9.6% |
| GPQA (HELM) | — | 52% |
| MMLU | — | 88.1% |

## Multimodal

- Claude Fable 5.1: 53.9 (#4)
- GPT-4o: 34.5 (#91)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| LMArena Vision | 1318 | 1137 |
| Video-MME | — | 71.9% |
| GeoBench | — | 71% |
| VPCT | — | 40% |
| Blueprint-Bench 2 | 41.9% | — |
| Furniture Assembly | 70% | — |
| LMArena Document | 1513 | — |
| ScienceQA | — | 88.5% |

## Multilingual

- Claude Fable 5.1: 59.1 (#3)
- GPT-4o: 43.2 (#186)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| LMArena Non-English | 1507 | 1283 |
| LMArena Chinese | 1586 | 1277 |
| LMArena French | 1525 | 1304 |
| LMArena German | 1500 | 1282 |
| LMArena Japanese | 1543 | 1257 |
| LMArena Korean | 1534 | 1234 |
| LMArena Russian | 1521 | 1286 |
| LMArena Spanish | 1516 | 1292 |

## Instruction Following

- Claude Fable 5.1: 79.2 (#6)
- GPT-4o: 66.6 (#207)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| LMArena Instruction Following | 1517 | 1278 |
| LiveBench Instruction Following | — | 68.6% |
| IFEval | — | 81.7% |

## Long Context

- Claude Fable 5.1: 46.7 (#20)
- GPT-4o: 39.4 (#179)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| LMArena Longer Query | 1522 | 1289 |
| Fiction.LiveBench | — | 66.7% |

## Writing & Preference

- Claude Fable 5.1: 79.2 (#2)
- GPT-4o: 52.6 (#166)

| Benchmark | Claude Fable 5.1 | GPT-4o |
|---|---|---|
| LMArena Text | 1510 | 1300 |
| LMArena Creative Writing | 1507 | 1292 |
| LMArena Multi-Turn | 1492 | 1302 |
| Short-Story Creative Writing | — | 81.8% |
| EQ-Bench Creative Writing | 2162 | — |
| WildBench | — | 82.8% |
| LiveBench Language | — | 47.6% |

## FAQ

### Is Claude Fable 5.1 better than GPT-4o?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 28.6 on the Noometry Index. GPT-4o costs 4.6× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

### Which is cheaper, Claude Fable 5.1 or GPT-4o?

GPT-4o is cheaper. It lists at $2.50 per million input tokens and $10 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

### Is Claude Fable 5.1 or GPT-4o better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 24.8 in the Noometry coding category.

### Which has the bigger context window?

Claude Fable 5.1 does, with 1M tokens against 128K.

### How many benchmarks do Claude Fable 5.1 and GPT-4o share?

31 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and GPT-4o has 72.