# Claude 2.1 vs GPT-5.1

> GPT-5.1 is the stronger model overall, scoring 48.8 to 24.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-gpt-5-1
- Last updated: 2026-10-10
- Shared benchmarks: 6

## Summary

- They share 6 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and GPT-5.1 in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-5.1 leads 50.3 to 9.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 88.6% for GPT-5.1.

## Snapshot

| | Claude 2.1 | GPT-5.1 |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 24.9 | 48.8 |
| Rank | 340 | 47 |
| Context | — | 400K |
| Input $/M | — | $1.25 |
| Output $/M | — | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2.1: 25.8 (#322)
- GPT-5.1: 46.9 (#59)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| WeirdML | 7.1% | 60.8% |
| SWE-bench Verified | — | 68% |
| SWE-bench Verified (bash only) | — | 66% |
| LMArena WebDev | — | 1395 |
| SciCode | — | 43.3% |
| GSO | — | 13.7% |
| LiveBench Coding | — | 72.5% |
| LMArena Coding | — | 1454 |
| ALE-Bench | — | 1,192 |

## Agentic & Tool Use

- Claude 2.1: —
- GPT-5.1: 32.5 (#55)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| Terminal-Bench | — | 47.6% |
| DeepResearch Bench | — | 42.8% |
| LMArena Search | — | 1199 |
| Vending-Bench 2 | — | 1,473 |

## Reasoning

- Claude 2.1: 20.6 (#216)
- GPT-5.1: 39.9 (#50)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| DTBench | 51% | 90.1% |
| Epoch Capabilities Index | 119.22 | 149.66 |
| ForecastBench | 54.2 | 58.1 |
| ARC-AGI-2 | — | 17.6% |
| SimpleBench | — | 53.2% |
| ARC-AGI-1 | — | 72.8% |
| CritPt | — | 4.9% |
| Chess Puzzles | — | 32% |
| EnigmaEval | — | 11.2% |
| LiveBench Reasoning | — | 95.8% |
| LMArena Hard Prompts | — | 1457 |
| Mystery Game Puzzles | — | 19% |
| LiveBench Data Analysis | — | 72.1% |
| LMCA | — | 43.9% |
| LiveBench | — | 78.8% |

## Math

- Claude 2.1: 9.6 (#309)
- GPT-5.1: 50.3 (#45)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 88.6% |
| Omni-MATH | — | 46.4% |
| LiveBench Math | — | 94.5% |
| LMArena Math | — | 1446 |
| FrontierMath (Feb 2025 set) | — | 31% |
| FrontierMath Tier 4 (v1) | — | 12.5% |

## Knowledge

- Claude 2.1: 15.5 (#287)
- GPT-5.1: 50.5 (#65)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| GPQA Diamond | 33% | 87.6% |
| Humanity's Last Exam | — | 23.7% |
| SimpleQA Verified | — | 48% |
| MMLU-Pro | — | 57.9% |
| Vectara Hallucination Rate | — | 10.9% |
| GPQA (HELM) | — | 44.2% |
| LMArena Expert | — | 1470 |
| MMLU | 73.5% | — |

## Multimodal

- Claude 2.1: —
- GPT-5.1: 44.0 (#17)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| LMArena Vision | — | 1250 |
| VPCT | — | 58.7% |
| LMArena Document | — | 1403 |

## Multilingual

- Claude 2.1: —
- GPT-5.1: 54.0 (#51)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| LMArena Non-English | — | 1431 |
| LMArena Chinese | — | 1495 |
| LMArena French | — | 1451 |
| LMArena German | — | 1439 |
| LMArena Japanese | — | 1453 |
| LMArena Korean | — | 1401 |
| LMArena Russian | — | 1435 |
| LMArena Spanish | — | 1430 |

## Instruction Following

- Claude 2.1: —
- GPT-5.1: 84.0 (#1)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| LiveBench Instruction Following | — | 93.3% |
| IFEval | — | 93.5% |
| LMArena Instruction Following | — | 1442 |

## Long Context

- Claude 2.1: —
- GPT-5.1: 47.6 (#14)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| CL-bench | — | 23.7% |
| CL-bench Life | — | 17.3% |
| LMArena Longer Query | — | 1448 |

## Writing & Preference

- Claude 2.1: —
- GPT-5.1: 64.7 (#53)

| Benchmark | Claude 2.1 | GPT-5.1 |
|---|---|---|
| LMArena Text | — | 1443 |
| LMArena Creative Writing | — | 1427 |
| WildBench | — | 86.3% |
| LMArena Multi-Turn | — | 1449 |
| LiveBench Language | — | 80.2% |

## FAQ

### Is Claude 2.1 better than GPT-5.1?

GPT-5.1 is the stronger model overall, scoring 48.8 to 24.9 on the Noometry Index.

### Is Claude 2.1 or GPT-5.1 better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.9 versus 25.8 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and GPT-5.1 share?

6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and GPT-5.1 has 63.