# Claude 2.1 vs Claude Sonnet 4

> Claude Sonnet 4 is the stronger model overall, scoring 40.6 to 24.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-claude-sonnet-4
- 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 Claude Sonnet 4 in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 4 leads 41.5 to 9.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 71.1% for Claude Sonnet 4.

## Snapshot

| | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 24.9 | 40.6 |
| Rank | 340 | 139 |
| Context | — | 200K |
| Input $/M | — | $3 |
| Output $/M | — | $15 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2.1: 25.8 (#322)
- Claude Sonnet 4: 44.0 (#70)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| WeirdML | 7.1% | 46.1% |
| SWE-bench Verified (bash only) | — | 64.9% |
| Aider Polyglot | — | 61.3% |
| SciCode | — | 40% |
| GSO | — | 4.9% |
| LMArena Coding | — | 1414 |
| ALE-Bench | — | 655.35 |

## Agentic & Tool Use

- Claude 2.1: —
- Claude Sonnet 4: 38.3 (#29)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| TheAgentCompany | — | 33.1% |
| Cybench | — | 35% |
| DeepResearch Bench | — | 46.6% |
| OSWorld | — | 43.9% |
| METR Time Horizons | — | 62% |

## Reasoning

- Claude 2.1: 20.6 (#216)
- Claude Sonnet 4: 23.0 (#169)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| DTBench | 51% | 77.1% |
| Epoch Capabilities Index | 119.22 | 141.69 |
| ForecastBench | 54.2 | 60.2 |
| ARC-AGI-2 | — | 5.9% |
| SimpleBench | — | 45.5% |
| Kagi LLM Benchmark | — | 73% |
| ARC-AGI-1 | — | 40% |
| CritPt | — | 0.3% |
| EnigmaEval | — | 3.1% |
| LMArena Hard Prompts | — | 1372 |
| LMCA | — | 29% |

## Math

- Claude 2.1: 9.6 (#309)
- Claude Sonnet 4: 41.5 (#71)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 71.1% |
| Omni-MATH | — | 60.2% |
| LMArena Math | — | 1375 |
| MATH Level 5 | — | 84.4% |
| FrontierMath (Feb 2025 set) | — | 4.1% |
| FrontierMath Tier 4 (v1) | — | 0% |

## Knowledge

- Claude 2.1: 15.5 (#287)
- Claude Sonnet 4: 41.6 (#99)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| GPQA Diamond | 33% | 79.2% |
| Humanity's Last Exam | — | 7.8% |
| MMLU-Pro | — | 84.3% |
| Confabulations | — | 13.2% |
| Vectara Hallucination Rate | — | 10.3% |
| GPQA (HELM) | — | 70.6% |
| LMArena Expert | — | 1371 |
| MMLU | 73.5% | — |

## Multimodal

- Claude 2.1: —
- Claude Sonnet 4: 25.6 (#116)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| LMArena Vision | — | 1191 |
| GeoBench | — | 37% |
| VPCT | — | 34% |
| MindCube | — | 44.8% |

## Multilingual

- Claude 2.1: —
- Claude Sonnet 4: 46.9 (#151)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| LMArena Non-English | — | 1333 |
| LMArena Chinese | — | 1351 |
| LMArena French | — | 1364 |
| LMArena German | — | 1331 |
| LMArena Japanese | — | 1301 |
| LMArena Korean | — | 1293 |
| LMArena Russian | — | 1355 |
| LMArena Spanish | — | 1356 |

## Instruction Following

- Claude 2.1: —
- Claude Sonnet 4: 71.8 (#141)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| IFEval | — | 84% |
| LMArena Instruction Following | — | 1375 |

## Long Context

- Claude 2.1: —
- Claude Sonnet 4: 33.6 (#254)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| Fiction.LiveBench | — | 46.9% |
| LMArena Longer Query | — | 1398 |

## Writing & Preference

- Claude 2.1: —
- Claude Sonnet 4: 57.3 (#127)

| Benchmark | Claude 2.1 | Claude Sonnet 4 |
|---|---|---|
| LMArena Text | — | 1351 |
| LMArena Creative Writing | — | 1345 |
| Short-Story Creative Writing | — | 81.4% |
| EQ-Bench Creative Writing | — | 1483 |
| WildBench | — | 83.8% |
| LMArena Multi-Turn | — | 1376 |

## FAQ

### Is Claude 2.1 better than Claude Sonnet 4?

Claude Sonnet 4 is the stronger model overall, scoring 40.6 to 24.9 on the Noometry Index.

### Is Claude 2.1 or Claude Sonnet 4 better for coding?

Claude Sonnet 4 scores higher on coding benchmarks: 44.0 versus 25.8 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and Claude Sonnet 4 share?

6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and Claude Sonnet 4 has 58.