# GPT-5.1 vs GPT-5 Pro

> GPT-5.1 is the stronger model overall, scoring 49.0 to 46.4 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-vs-gpt-5-pro
- Last updated: 2026-10-10
- Shared benchmarks: 8

## Summary

- They share 8 benchmarks with published results for both. GPT-5.1 scores higher in 3 categories and GPT-5 Pro in 1 category; 3 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where GPT-5 Pro leads 56.7 to 50.6.
- The biggest single-benchmark swing is SimpleBench: 53.2% for GPT-5.1 and 61.6% for GPT-5 Pro.
- GPT-5.1 is cheaper at $1.25 / $10 per million input/output tokens, against $15 / $120 for GPT-5 Pro.

## Snapshot

| | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 49.0 | 46.4 |
| Rank | 53 | 64 |
| Context | 400K | 400K |
| Input $/M | $1.25 | $15 |
| Output $/M | $10 | $120 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.1: 46.4 (#66)
- GPT-5 Pro: 44.0 (#80)

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| WeirdML | 60.8% | 60.4% |
| 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 | — |
| AlgoTune | — | 1.31 |

## Agentic & Tool Use

- GPT-5.1: 32.7 (#60)
- GPT-5 Pro: —

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| Terminal-Bench | 47.6% | — |
| DeepResearch Bench | 42.8% | — |
| LMArena Search | 1199 | — |
| Vending-Bench 2 | 1,473 | — |

## Reasoning

- GPT-5.1: 39.8 (#58)
- GPT-5 Pro: 38.9 (#62)

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| ARC-AGI-2 | 17.6% | 18.3% |
| SimpleBench | 53.2% | 61.6% |
| ARC-AGI-1 | 72.8% | 70.2% |
| EnigmaEval | 11.2% | 18.8% |
| Epoch Capabilities Index | 149.64 | 150.28 |
| Kagi LLM Benchmark | — | 76.8% |
| CritPt | 4.9% | — |
| Chess Puzzles | 32% | — |
| LiveBench Reasoning | 95.8% | — |
| LMArena Hard Prompts | 1457 | — |
| Mystery Game Puzzles | 19% | — |
| DTBench | 90.1% | — |
| LiveBench Data Analysis | 72.1% | — |
| LMCA | 43.9% | — |
| ForecastBench | 58.1 | — |
| LiveBench | 78.8% | — |

## Math

- GPT-5.1: 52.2 (#51)
- GPT-5 Pro: 48.5 (#63)

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| FrontierMath Tier 4 (v1) | 12.5% | 14.6% |
| FrontierMath (Tiers 1-3) | — | 55.8% |
| FrontierMath Tier 4 | — | 19.5% |
| OTIS Mock AIME 2024-2025 | 88.6% | — |
| Omni-MATH | 46.4% | — |
| LiveBench Math | 94.5% | — |
| LMArena Math | 1447 | — |
| FrontierMath (Feb 2025 set) | 31% | — |

## Knowledge

- GPT-5.1: 50.6 (#71)
- GPT-5 Pro: 56.7 (#42)

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| Humanity's Last Exam | 23.7% | 31.6% |
| GPQA Diamond | 87.6% | — |
| SimpleQA Verified | 48% | — |
| MMLU-Pro | 57.9% | — |
| Vectara Hallucination Rate | 10.9% | — |
| GPQA (HELM) | 44.2% | — |
| LMArena Expert | 1470 | — |

## Multimodal

- GPT-5.1: 44.8 (#19)
- GPT-5 Pro: —

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Vision | 1250 | — |
| VPCT | 58.7% | — |
| LMArena Document | 1403 | — |

## Multilingual

- GPT-5.1: 53.8 (#56)
- GPT-5 Pro: —

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Non-English | 1431 | — |
| LMArena Chinese | 1495 | — |
| LMArena French | 1450 | — |
| LMArena German | 1438 | — |
| LMArena Japanese | 1453 | — |
| LMArena Korean | 1401 | — |
| LMArena Russian | 1435 | — |
| LMArena Spanish | 1433 | — |

## Instruction Following

- GPT-5.1: 83.9 (#1)
- GPT-5 Pro: —

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

## Long Context

- GPT-5.1: 47.6 (#14)
- GPT-5 Pro: —

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

## Writing & Preference

- GPT-5.1: 64.5 (#55)
- GPT-5 Pro: —

| Benchmark | GPT-5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Text | 1443 | — |
| LMArena Creative Writing | 1427 | — |
| WildBench | 86.3% | — |
| LMArena Multi-Turn | 1450 | — |
| LiveBench Language | 80.2% | — |

## FAQ

### Is GPT-5.1 better than GPT-5 Pro?

GPT-5.1 is the stronger model overall, scoring 49.0 to 46.4 on the Noometry Index.

### Which is cheaper, GPT-5.1 or GPT-5 Pro?

GPT-5.1 is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-5 Pro lists at $15 and $120.

### Is GPT-5.1 or GPT-5 Pro better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 44.0 in the Noometry coding category.

### Which has the bigger context window?

Both accept 400K tokens.

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

8 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and GPT-5 Pro has 12.