# Claude 3 Sonnet vs GPT-5.5 Instant

> GPT-5.5 Instant is the stronger model overall, scoring 42.7 to 29.0 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-3-sonnet-vs-gpt-5-5-instant
- Last updated: 2026-10-10
- Shared benchmarks: 21

## Summary

- They share 21 benchmarks with published results for both. Claude 3 Sonnet scores higher in 0 categories and GPT-5.5 Instant in 9 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where GPT-5.5 Instant leads 48.9 to 21.1.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 2.5% for Claude 3 Sonnet and 68.1% for GPT-5.5 Instant.

## Snapshot

| | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 29.0 | 42.7 |
| Rank | 319 | 110 |
| Context | — | — |
| Input $/M | — | — |
| Output $/M | — | — |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 3 Sonnet: 29.6 (#302)
- GPT-5.5 Instant: 44.3 (#74)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Coding | 1223 | 1433 |
| SciCode | — | 48.6% |
| WeirdML | 10.2% | — |
| BigCodeBench Instruct | 42.7% | — |
| BigCodeBench Complete | 53.8% | — |
| HumanEval+ | 64% | — |
| MBPP+ | 69.3% | — |

## Reasoning

- Claude 3 Sonnet: 20.5 (#237)
- GPT-5.5 Instant: 24.9 (#155)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Hard Prompts | 1197 | 1426 |
| Epoch Capabilities Index | 120.7 | 142.52 |
| CritPt | — | 0% |
| Chess Puzzles | — | 12% |
| DTBench | 53.6% | — |
| WinoGrande | 75.1% | — |

## Math

- Claude 3 Sonnet: 10.7 (#310)
- GPT-5.5 Instant: 26.5 (#259)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 2.5% | 68.1% |
| LMArena Math | 1213 | 1420 |
| FrontierMath (Tiers 1-3) | — | 26.3% |
| FrontierMath Tier 4 | — | 2.4% |
| MATH Level 5 | 18.2% | — |

## Knowledge

- Claude 3 Sonnet: 21.1 (#276)
- GPT-5.5 Instant: 48.9 (#74)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| GPQA Diamond | 40.6% | 82.5% |
| LMArena Expert | 1173 | 1409 |
| MMLU | 75.9% | — |

## Multimodal

- Claude 3 Sonnet: 25.2 (#125)
- GPT-5.5 Instant: 40.0 (#52)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | 984 | 1250 |
| LMArena Document | — | 1403 |

## Multilingual

- Claude 3 Sonnet: 37.8 (#234)
- GPT-5.5 Instant: 52.8 (#80)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1205 | 1417 |
| LMArena Chinese | 1189 | 1456 |
| LMArena French | 1229 | 1428 |
| LMArena German | 1204 | 1411 |
| LMArena Japanese | 1131 | 1408 |
| LMArena Korean | 1128 | 1392 |
| LMArena Russian | 1227 | 1431 |
| LMArena Spanish | 1204 | 1429 |

## Instruction Following

- Claude 3 Sonnet: 62.8 (#235)
- GPT-5.5 Instant: 74.2 (#100)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1199 | 1406 |

## Long Context

- Claude 3 Sonnet: 36.7 (#228)
- GPT-5.5 Instant: 43.4 (#96)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1211 | 1422 |

## Writing & Preference

- Claude 3 Sonnet: 42.1 (#238)
- GPT-5.5 Instant: 61.8 (#85)

| Benchmark | Claude 3 Sonnet | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1218 | 1419 |
| LMArena Creative Writing | 1186 | 1419 |
| LMArena Multi-Turn | 1227 | 1433 |

## FAQ

### Is Claude 3 Sonnet better than GPT-5.5 Instant?

GPT-5.5 Instant is the stronger model overall, scoring 42.7 to 29.0 on the Noometry Index.

### Is Claude 3 Sonnet or GPT-5.5 Instant better for coding?

GPT-5.5 Instant scores higher on coding benchmarks: 44.3 versus 29.6 in the Noometry coding category.

### How many benchmarks do Claude 3 Sonnet and GPT-5.5 Instant share?

21 benchmarks have published results for both models. Claude 3 Sonnet has 30 scored results on Noometry and GPT-5.5 Instant has 27.