# gpt-oss-120b vs Mercury

> Mercury is the stronger model overall, scoring 37.6 to 36.3 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-oss-120b-vs-mercury
- Last updated: 2026-10-10
- Shared benchmarks: 9

## Summary

- They share 9 benchmarks with published results for both. gpt-oss-120b scores higher in 4 categories and Mercury in 2 categories; 5 gaps are clear of the uncertainty.
- The widest gap is in long context, where Mercury leads 38.4 to 31.4.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 58.6% for gpt-oss-120b and 21.6% for Mercury.
- gpt-oss-120b has downloadable open weights; the other is API-only.

## Snapshot

| | gpt-oss-120b | Mercury |
|---|---|---|
| Provider | OpenAI | Inception |
| Noometry Index | 36.3 | 37.6 |
| Rank | 217 | 199 |
| Context | 131K | — |
| Input $/M | $0.037 | — |
| Output $/M | $0.17 | — |
| Weights | Open | Proprietary |

## Coding

- gpt-oss-120b: 33.5 (#256)
- Mercury: 38.7 (#170)

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| LMArena Coding | 1380 | 1322 |
| SWE-bench Verified (bash only) | 26% | — |
| Aider Polyglot | 41.8% | — |
| SciCode | 36% | — |
| WeirdML | 48.2% | — |
| ALE-Bench | 575.62 | — |
| AlgoTune | 1.41 | — |

## Agentic & Tool Use

- gpt-oss-120b: 12.2 (#153)
- Mercury: —

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| Terminal-Bench | 18.7% | — |
| APEX-Agents | 4.4% | — |
| METR Time Horizons | 56.6% | — |
| Vending-Bench 2 | -21.53 | — |

## Reasoning

- gpt-oss-120b: 20.0 (#245)
- Mercury: 17.5 (#293)

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| Kagi LLM Benchmark | 58.6% | 21.6% |
| LMArena Hard Prompts | 1364 | 1285 |
| SimpleBench | 22.1% | — |
| CritPt | 1.1% | — |
| Chess Puzzles | 20% | — |
| Mystery Game Puzzles | 2% | — |
| DTBench | 76.3% | — |
| LMCA | 22.1% | — |
| Surface Evolver Bench | 25% | — |
| Epoch Capabilities Index | 139.93 | — |

## Math

- gpt-oss-120b: 52.5 (#50)
- Mercury: —

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 88.9% | — |
| Omni-MATH | 68.8% | — |
| LMArena Math | 1389 | — |

## Knowledge

- gpt-oss-120b: 42.4 (#96)
- Mercury: —

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| GPQA Diamond | 75.8% | — |
| MMLU-Pro | 79.5% | — |
| Confabulations | 15.7% | — |
| Vectara Hallucination Rate | 14.2% | — |
| GPQA (HELM) | 68.4% | — |
| LMArena Expert | 1356 | — |

## Multilingual

- gpt-oss-120b: 48.0 (#147)
- Mercury: 41.6 (#206)

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| LMArena Non-English | 1351 | 1260 |
| LMArena Chinese | 1385 | — |
| LMArena French | 1369 | — |
| LMArena German | 1353 | — |
| LMArena Japanese | 1331 | — |
| LMArena Korean | 1282 | — |
| LMArena Russian | 1343 | — |
| LMArena Spanish | 1389 | — |

## Instruction Following

- gpt-oss-120b: 69.3 (#173)
- Mercury: 65.2 (#224)

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| LMArena Instruction Following | 1318 | 1239 |
| IFEval | 83.6% | — |

## Long Context

- gpt-oss-120b: 31.4 (#278)
- Mercury: 38.4 (#198)

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| LMArena Longer Query | 1319 | 1266 |
| Fiction.LiveBench | 44.4% | — |

## Writing & Preference

- gpt-oss-120b: 46.5 (#217)
- Mercury: 46.2 (#221)

| Benchmark | gpt-oss-120b | Mercury |
|---|---|---|
| LMArena Text | 1365 | 1282 |
| LMArena Creative Writing | 1275 | 1191 |
| LMArena Multi-Turn | 1340 | 1282 |
| Short-Story Creative Writing | 77.1% | — |
| EQ-Bench Creative Writing | 961 | — |
| WildBench | 84.5% | — |

## FAQ

### Is gpt-oss-120b better than Mercury?

Mercury is the stronger model overall, scoring 37.6 to 36.3 on the Noometry Index.

### Is gpt-oss-120b or Mercury better for coding?

Mercury scores higher on coding benchmarks: 38.7 versus 33.5 in the Noometry coding category.

### How many benchmarks do gpt-oss-120b and Mercury share?

9 benchmarks have published results for both models. gpt-oss-120b has 48 scored results on Noometry and Mercury has 9.