# Claude 2.1 vs gpt-oss-20b

> gpt-oss-20b is the stronger model overall, scoring 32.1 to 24.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-gpt-oss-20b
- Last updated: 2026-10-10
- Shared benchmarks: 5

## Summary

- They share 5 benchmarks with published results for both. Claude 2.1 scores higher in 1 category and gpt-oss-20b in 3 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where gpt-oss-20b leads 37.6 to 9.6.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 65.3% for gpt-oss-20b.
- gpt-oss-20b has downloadable open weights; the other is API-only.

## Snapshot

| | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 24.9 | 32.1 |
| Rank | 340 | 249 |
| Context | — | 131K |
| Input $/M | — | $0.018 |
| Output $/M | — | $0.09 |
| Weights | Proprietary | Open |

## Coding

- Claude 2.1: 25.8 (#322)
- gpt-oss-20b: 37.1 (#185)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| WeirdML | 7.1% | 40.9% |
| SciCode | — | 34.4% |
| LMArena Coding | — | 1307 |
| ALE-Bench | — | 566.05 |

## Agentic & Tool Use

- Claude 2.1: —
- gpt-oss-20b: 9.2 (#146)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| Terminal-Bench | — | 3.4% |

## Reasoning

- Claude 2.1: 20.6 (#216)
- gpt-oss-20b: 18.8 (#251)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| DTBench | 51% | 68% |
| Epoch Capabilities Index | 119.22 | 137.81 |
| Kagi LLM Benchmark | — | 53.2% |
| CritPt | — | 1.4% |
| Chess Puzzles | — | 4% |
| LMArena Hard Prompts | — | 1274 |
| LMCA | — | 14.5% |
| ForecastBench | 54.2 | — |

## Math

- Claude 2.1: 9.6 (#309)
- gpt-oss-20b: 37.6 (#93)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 65.3% |
| Omni-MATH | — | 56.5% |
| LMArena Math | — | 1317 |

## Knowledge

- Claude 2.1: 15.5 (#287)
- gpt-oss-20b: 34.6 (#186)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| GPQA Diamond | 33% | 60.8% |
| MMLU-Pro | — | 74% |
| GPQA (HELM) | — | 59.4% |
| LMArena Expert | — | 1258 |
| MMLU | 73.5% | — |

## Multilingual

- Claude 2.1: —
- gpt-oss-20b: 42.4 (#192)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| LMArena Non-English | — | 1269 |
| LMArena Chinese | — | 1311 |
| LMArena German | — | 1249 |
| LMArena Japanese | — | 1245 |
| LMArena Korean | — | 1239 |
| LMArena Russian | — | 1279 |
| LMArena Spanish | — | 1267 |

## Instruction Following

- Claude 2.1: —
- gpt-oss-20b: 62.0 (#235)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| IFEval | — | 73.2% |
| LMArena Instruction Following | — | 1236 |

## Long Context

- Claude 2.1: —
- gpt-oss-20b: 37.9 (#203)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| LMArena Longer Query | — | 1251 |

## Writing & Preference

- Claude 2.1: —
- gpt-oss-20b: 35.8 (#260)

| Benchmark | Claude 2.1 | gpt-oss-20b |
|---|---|---|
| LMArena Text | — | 1288 |
| LMArena Creative Writing | — | 1201 |
| EQ-Bench Creative Writing | — | 666 |
| WildBench | — | 73.7% |
| LMArena Multi-Turn | — | 1268 |

## FAQ

### Is Claude 2.1 better than gpt-oss-20b?

gpt-oss-20b is the stronger model overall, scoring 32.1 to 24.9 on the Noometry Index.

### Is Claude 2.1 or gpt-oss-20b better for coding?

gpt-oss-20b scores higher on coding benchmarks: 37.1 versus 25.8 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and gpt-oss-20b share?

5 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and gpt-oss-20b has 34.