# Claude Opus 5 vs GPT-5.1

> Claude Opus 5 is the stronger model overall, scoring 67.8 to 49.0 on the Noometry Index. GPT-5.1 costs 2.9× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-opus-5-vs-gpt-5-1
- Last updated: 2026-10-10
- Shared benchmarks: 36

## Summary

- They share 36 benchmarks with published results for both. Claude Opus 5 scores higher in 8 categories and GPT-5.1 in 2 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 5 leads 77.2 to 39.8.
- The biggest single-benchmark swing is ARC-AGI-2: 90.4% for Claude Opus 5 and 17.6% for GPT-5.1.
- GPT-5.1 is cheaper at $1.25 / $10 per million input/output tokens, against $5 / $25 for Claude Opus 5.
- Claude Opus 5 accepts more context: 1M tokens versus 400K.

## Snapshot

| | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 67.8 | 49.0 |
| Rank | 4 | 53 |
| Context | 1M | 400K |
| Input $/M | $5 | $1.25 |
| Output $/M | $25 | $10 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 5: 67.5 (#5)
- GPT-5.1: 46.4 (#66)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| LMArena WebDev | 1691 | 1395 |
| SciCode | 56.4% | 43.3% |
| WeirdML | 91.8% | 60.8% |
| LMArena Coding | 1534 | 1454 |
| ALE-Bench | 2,165 | 1,192 |
| SWE-bench Verified | — | 68% |
| DeepSWE | 73.6% | — |
| FrontierCode | 53.4% | — |
| SWE-bench Verified (bash only) | — | 66% |
| CursorBench | 46.6% | — |
| FrontierSWE | 52% | — |
| GSO | — | 13.7% |
| LiveBench Coding | — | 72.5% |

## Agentic & Tool Use

- Claude Opus 5: 55.6 (#1)
- GPT-5.1: 32.7 (#60)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| Vending-Bench 2 | 11,182 | 1,473 |
| Terminal-Bench | — | 47.6% |
| APEX-Agents | 65.8% | — |
| OSWorld 2.0 | 31.4% | — |
| τ²-bench Banking | 48.7% | — |
| DeepResearch Bench | — | 42.8% |
| PostTrainBench | 35% | — |
| BALROG | 63.4% | — |
| GBAEval | 79.6% | — |
| GDP.pdf | 24% | — |
| LMArena Search | — | 1199 |

## Reasoning

- Claude Opus 5: 77.2 (#4)
- GPT-5.1: 39.8 (#58)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| ARC-AGI-2 | 90.4% | 17.6% |
| SimpleBench | 80.6% | 53.2% |
| ARC-AGI-1 | 97.5% | 72.8% |
| CritPt | 29.1% | 4.9% |
| Chess Puzzles | 42% | 32% |
| LMArena Hard Prompts | 1526 | 1457 |
| Mystery Game Puzzles | 59% | 19% |
| DTBench | 97.9% | 90.1% |
| LMCA | 64.5% | 43.9% |
| Epoch Capabilities Index | 162.78 | 149.64 |
| NYT Connections (extended) | 94.3% | — |
| EnigmaEval | — | 11.2% |
| EBR-Bench | 45.7% | — |
| LiveBench Reasoning | — | 95.8% |
| LiveBench Data Analysis | — | 72.1% |
| Bench to the Future 3 | 0.12 | — |
| ForecastBench | — | 58.1 |
| LiveBench | — | 78.8% |

## Math

- Claude Opus 5: 86.2 (#8)
- GPT-5.1: 52.2 (#51)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 98.9% | 88.6% |
| LMArena Math | 1531 | 1447 |
| FrontierMath (Tiers 1-3) | 85.6% | — |
| FrontierMath Tier 4 | 73.2% | — |
| ProofBench | 99% | — |
| Omni-MATH | — | 46.4% |
| LiveBench Math | — | 94.5% |
| FrontierMath (Feb 2025 set) | — | 31% |
| FrontierMath Tier 4 (v1) | — | 12.5% |

## Knowledge

- Claude Opus 5: 66.8 (#9)
- GPT-5.1: 50.6 (#71)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| GPQA Diamond | 93.9% | 87.6% |
| SimpleQA Verified | 59.9% | 48% |
| LMArena Expert | 1557 | 1470 |
| Humanity's Last Exam | — | 23.7% |
| MMLU-Pro | — | 57.9% |
| Vectara Hallucination Rate | — | 10.9% |
| GPQA (HELM) | — | 44.2% |

## Multimodal

- Claude Opus 5: 50.8 (#8)
- GPT-5.1: 44.8 (#19)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| LMArena Vision | 1319 | 1250 |
| LMArena Document | 1516 | 1403 |
| VPCT | — | 58.7% |
| Blueprint-Bench 2 | 30.4% | — |
| Furniture Assembly | 60.8% | — |

## Multilingual

- Claude Opus 5: 58.8 (#4)
- GPT-5.1: 53.8 (#56)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| LMArena Non-English | 1501 | 1431 |
| LMArena Chinese | 1574 | 1495 |
| LMArena French | 1519 | 1450 |
| LMArena German | 1524 | 1438 |
| LMArena Japanese | 1516 | 1453 |
| LMArena Korean | 1521 | 1401 |
| LMArena Russian | 1507 | 1435 |
| LMArena Spanish | 1519 | 1433 |

## Instruction Following

- Claude Opus 5: 79.2 (#7)
- GPT-5.1: 83.9 (#1)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| LMArena Instruction Following | 1517 | 1443 |
| LiveBench Instruction Following | — | 93.3% |
| IFEval | — | 93.5% |

## Long Context

- Claude Opus 5: 46.5 (#21)
- GPT-5.1: 47.6 (#14)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| LMArena Longer Query | 1515 | 1447 |
| CL-bench | — | 23.7% |
| CL-bench Life | — | 17.3% |

## Writing & Preference

- Claude Opus 5: 79.2 (#1)
- GPT-5.1: 64.5 (#55)

| Benchmark | Claude Opus 5 | GPT-5.1 |
|---|---|---|
| LMArena Text | 1507 | 1443 |
| LMArena Creative Writing | 1491 | 1427 |
| LMArena Multi-Turn | 1499 | 1450 |
| EQ-Bench Creative Writing | 2133 | — |
| WildBench | — | 86.3% |
| EQ-Bench 4 | 1385 | — |
| LiveBench Language | — | 80.2% |

## FAQ

### Is Claude Opus 5 better than GPT-5.1?

Claude Opus 5 is the stronger model overall, scoring 67.8 to 49.0 on the Noometry Index. GPT-5.1 costs 2.9× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

### Which is cheaper, Claude Opus 5 or GPT-5.1?

GPT-5.1 is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; Claude Opus 5 lists at $5 and $25.

### Is Claude Opus 5 or GPT-5.1 better for coding?

Claude Opus 5 scores higher on coding benchmarks: 67.5 versus 46.4 in the Noometry coding category.

### Which has the bigger context window?

Claude Opus 5 does, with 1M tokens against 400K.

### How many benchmarks do Claude Opus 5 and GPT-5.1 share?

36 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and GPT-5.1 has 63.