# Claude Opus 4.6 vs gpt-oss-120b

> Claude Opus 4.6 is the stronger model overall, scoring 58.2 to 36.3 on the Noometry Index. gpt-oss-120b costs 142× less per token, which makes it the better buy when Claude Opus 4.6's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-opus-4-6-vs-gpt-oss-120b
- Last updated: 2026-10-10
- Shared benchmarks: 36

## Summary

- They share 36 benchmarks with published results for both. Claude Opus 4.6 scores higher in 9 categories and gpt-oss-120b in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in agentic & tool use, where Claude Opus 4.6 leads 51.1 to 12.2.
- The biggest single-benchmark swing is Terminal-Bench: 79.8% for Claude Opus 4.6 and 18.7% for gpt-oss-120b.
- gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $5 / $25 for Claude Opus 4.6.
- Claude Opus 4.6 accepts more context: 1M tokens versus 131K.
- gpt-oss-120b has downloadable open weights; the other is API-only.

## Snapshot

| | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 58.2 | 36.3 |
| Rank | 20 | 217 |
| Context | 1M | 131K |
| Input $/M | $5 | $0.037 |
| Output $/M | $25 | $0.17 |
| Weights | Proprietary | Open |

## Coding

- Claude Opus 4.6: 57.2 (#20)
- gpt-oss-120b: 33.5 (#256)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| SWE-bench Verified (bash only) | 75.6% | 26% |
| WeirdML | 78% | 48.2% |
| LMArena Coding | 1536 | 1380 |
| ALE-Bench | 996.5 | 575.62 |
| AlgoTune | 1.47 | 1.41 |
| SWE-bench Verified | 78.7% | — |
| FrontierCode | 26.6% | — |
| Aider Polyglot | — | 41.8% |
| LMArena WebDev | 1547 | — |
| SWE-bench Multilingual | 72% | — |
| SciCode | — | 36% |
| GSO | 41.2% | — |

## Agentic & Tool Use

- Claude Opus 4.6: 51.1 (#4)
- gpt-oss-120b: 12.2 (#153)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| Terminal-Bench | 79.8% | 18.7% |
| APEX-Agents | 46.3% | 4.4% |
| METR Time Horizons | 78.9% | 56.6% |
| Vending-Bench 2 | 8,018 | -21.53 |
| Remote Labor Index | 4.2% | — |
| τ²-bench Banking | 27.3% | — |
| Cybench | 93% | — |
| DeepResearch Bench | 55.3% | — |
| GBAEval | 44.1% | — |
| LMArena Search | 1253 | — |

## Reasoning

- Claude Opus 4.6: 57.8 (#23)
- gpt-oss-120b: 20.0 (#245)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| SimpleBench | 67.6% | 22.1% |
| Kagi LLM Benchmark | 83.6% | 58.6% |
| Chess Puzzles | 17% | 20% |
| LMArena Hard Prompts | 1527 | 1364 |
| Mystery Game Puzzles | 25% | 2% |
| DTBench | 91.2% | 76.3% |
| LMCA | 55.8% | 22.1% |
| Epoch Capabilities Index | 155.24 | 139.93 |
| ARC-AGI-2 | 69.2% | — |
| NYT Connections (extended) | 92.1% | — |
| ARC-AGI-1 | 94% | — |
| CritPt | — | 1.1% |
| EnigmaEval | 7.6% | — |
| Thematic Generalization | 80.6% | — |
| EBR-Bench | 12.7% | — |
| Surface Evolver Bench | — | 25% |
| ForecastBench | 60 | — |

## Math

- Claude Opus 4.6: 63.0 (#31)
- gpt-oss-120b: 52.5 (#50)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 94.4% | 88.9% |
| LMArena Math | 1519 | 1389 |
| FrontierMath (Tiers 1-3) | 66% | — |
| FrontierMath Tier 4 | 26.8% | — |
| MathArena Final-Answer Competitions | 78.5% | — |
| ProofBench | 50% | — |
| Omni-MATH | — | 68.8% |
| FrontierMath (Feb 2025 set) | 40.7% | — |
| FrontierMath Tier 4 (v1) | 22.9% | — |

## Knowledge

- Claude Opus 4.6: 61.9 (#26)
- gpt-oss-120b: 42.4 (#96)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| GPQA Diamond | 90.5% | 75.8% |
| Vectara Hallucination Rate | 12.2% | 14.2% |
| LMArena Expert | 1546 | 1356 |
| Humanity's Last Exam | 34.4% | — |
| SimpleQA Verified | 47% | — |
| MMLU-Pro | — | 79.5% |
| Confabulations | — | 15.7% |
| GPQA (HELM) | — | 68.4% |

## Multimodal

- Claude Opus 4.6: 37.3 (#74)
- gpt-oss-120b: —

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| LMArena Vision | 1316 | — |
| Furniture Assembly | 28.3% | — |
| LMArena Document | 1507 | — |

## Multilingual

- Claude Opus 4.6: 57.9 (#6)
- gpt-oss-120b: 48.0 (#147)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| LMArena Non-English | 1489 | 1351 |
| LMArena Chinese | 1551 | 1385 |
| LMArena French | 1513 | 1369 |
| LMArena German | 1502 | 1353 |
| LMArena Japanese | 1484 | 1331 |
| LMArena Korean | 1464 | 1282 |
| LMArena Russian | 1497 | 1343 |
| LMArena Spanish | 1510 | 1389 |

## Instruction Following

- Claude Opus 4.6: 79.5 (#4)
- gpt-oss-120b: 69.3 (#173)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| LMArena Instruction Following | 1523 | 1318 |
| IFEval | — | 83.6% |

## Long Context

- Claude Opus 4.6: 48.1 (#13)
- gpt-oss-120b: 31.4 (#278)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| LMArena Longer Query | 1520 | 1319 |
| Fiction.LiveBench | — | 44.4% |
| CL-bench | 20.7% | — |
| CL-bench Life | 17% | — |

## Writing & Preference

- Claude Opus 4.6: 73.5 (#10)
- gpt-oss-120b: 46.5 (#217)

| Benchmark | Claude Opus 4.6 | gpt-oss-120b |
|---|---|---|
| LMArena Text | 1503 | 1365 |
| LMArena Creative Writing | 1505 | 1275 |
| EQ-Bench Creative Writing | 1809 | 961 |
| LMArena Multi-Turn | 1513 | 1340 |
| Short-Story Creative Writing | — | 77.1% |
| WildBench | — | 84.5% |
| EQ-Bench 4 | 1223 | — |

## FAQ

### Is Claude Opus 4.6 better than gpt-oss-120b?

Claude Opus 4.6 is the stronger model overall, scoring 58.2 to 36.3 on the Noometry Index. gpt-oss-120b costs 142× less per token, which makes it the better buy when Claude Opus 4.6's lead doesn't matter for your workload.

### Which is cheaper, Claude Opus 4.6 or gpt-oss-120b?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; Claude Opus 4.6 lists at $5 and $25.

### Is Claude Opus 4.6 or gpt-oss-120b better for coding?

Claude Opus 4.6 scores higher on coding benchmarks: 57.2 versus 33.5 in the Noometry coding category.

### Which has the bigger context window?

Claude Opus 4.6 does, with 1M tokens against 131K.

### How many benchmarks do Claude Opus 4.6 and gpt-oss-120b share?

36 benchmarks have published results for both models. Claude Opus 4.6 has 68 scored results on Noometry and gpt-oss-120b has 48.