# Claude 2.1 vs Claude 3.5 Sonnet

> Claude 3.5 Sonnet is the stronger model overall, scoring 34.4 to 24.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-claude-3-5-sonnet
- Last updated: 2026-10-10
- Shared benchmarks: 7

## Summary

- They share 7 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and Claude 3.5 Sonnet in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in coding, where Claude 3.5 Sonnet leads 39.5 to 25.8.
- The biggest single-benchmark swing is WeirdML: 7.1% for Claude 2.1 and 40% for Claude 3.5 Sonnet.

## Snapshot

| | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 24.9 | 34.4 |
| Rank | 340 | 225 |
| Context | — | — |
| Input $/M | — | — |
| Output $/M | — | — |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2.1: 25.8 (#322)
- Claude 3.5 Sonnet: 39.5 (#145)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| WeirdML | 7.1% | 40% |
| Aider Polyglot | — | 51.6% |
| GSO | — | 4.6% |
| BigCodeBench Instruct | — | 46.8% |
| LiveBench Coding | — | 67.1% |
| LMArena Coding | — | 1343 |
| BigCodeBench Complete | — | 58.6% |
| CadEval | — | 48% |
| HumanEval+ | — | 81.7% |
| MBPP+ | — | 74.3% |

## Agentic & Tool Use

- Claude 2.1: —
- Claude 3.5 Sonnet: 32.1 (#61)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| TheAgentCompany | — | 24% |
| Cybench | — | 17.5% |
| BALROG | — | 32.6% |
| METR Time Horizons | — | 45.2% |

## Reasoning

- Claude 2.1: 20.6 (#216)
- Claude 3.5 Sonnet: 22.5 (#176)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| DTBench | 51% | 67.8% |
| Epoch Capabilities Index | 119.22 | 133.55 |
| ForecastBench | 54.2 | 60.7 |
| SimpleBench | — | 41.4% |
| EnigmaEval | — | 0.9% |
| LiveBench Reasoning | — | 56.7% |
| LMArena Hard Prompts | — | 1305 |
| LiveBench Data Analysis | — | 55% |
| LiveBench | — | 59% |

## Math

- Claude 2.1: 9.6 (#309)
- Claude 3.5 Sonnet: 18.0 (#282)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 8.5% |
| Omni-MATH | — | 27.6% |
| LiveBench Math | — | 52.3% |
| LMArena Math | — | 1306 |
| MATH Level 5 | — | 56.9% |
| FrontierMath (Feb 2025 set) | — | 2.1% |
| FrontierMath Tier 4 (v1) | — | 0% |

## Knowledge

- Claude 2.1: 15.5 (#287)
- Claude 3.5 Sonnet: 28.5 (#236)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| GPQA Diamond | 33% | 55.3% |
| MMLU | 73.5% | 87.3% |
| Humanity's Last Exam | — | 4.1% |
| MMLU-Pro | — | 77.7% |
| Confabulations | — | 19.9% |
| GPQA (HELM) | — | 56.5% |
| LMArena Expert | — | 1264 |

## Multimodal

- Claude 2.1: —
- Claude 3.5 Sonnet: 26.0 (#115)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| LMArena Vision | — | 1125 |
| Video-MME | — | 60% |
| GeoBench | — | 62% |
| VPCT | — | 33% |

## Multilingual

- Claude 2.1: —
- Claude 3.5 Sonnet: 43.4 (#180)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| LMArena Non-English | — | 1283 |
| LMArena Chinese | — | 1271 |
| LMArena French | — | 1304 |
| LMArena German | — | 1297 |
| LMArena Japanese | — | 1234 |
| LMArena Korean | — | 1200 |
| LMArena Russian | — | 1305 |
| LMArena Spanish | — | 1289 |

## Instruction Following

- Claude 2.1: —
- Claude 3.5 Sonnet: 69.0 (#177)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| LiveBench Instruction Following | — | 69.3% |
| IFEval | — | 85.5% |
| LMArena Instruction Following | — | 1297 |

## Long Context

- Claude 2.1: —
- Claude 3.5 Sonnet: 39.9 (#162)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| LMArena Longer Query | — | 1311 |

## Writing & Preference

- Claude 2.1: —
- Claude 3.5 Sonnet: 53.0 (#159)

| Benchmark | Claude 2.1 | Claude 3.5 Sonnet |
|---|---|---|
| LMArena Text | — | 1298 |
| LMArena Creative Writing | — | 1292 |
| Short-Story Creative Writing | — | 80.3% |
| EQ-Bench Creative Writing | — | 1451 |
| WildBench | — | 79.2% |
| LMArena Multi-Turn | — | 1326 |
| LiveBench Language | — | 53.8% |

## FAQ

### Is Claude 2.1 better than Claude 3.5 Sonnet?

Claude 3.5 Sonnet is the stronger model overall, scoring 34.4 to 24.9 on the Noometry Index.

### Is Claude 2.1 or Claude 3.5 Sonnet better for coding?

Claude 3.5 Sonnet scores higher on coding benchmarks: 39.5 versus 25.8 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and Claude 3.5 Sonnet share?

7 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and Claude 3.5 Sonnet has 60.