# gpt-oss-120b vs Qwen3.5 Plus

> Qwen3.5 Plus is the stronger model overall, scoring 42.9 to 36.3 on the Noometry Index. gpt-oss-120b costs 13× less per token, which makes it the better buy when Qwen3.5 Plus's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-oss-120b-vs-qwen3-5-plus
- Last updated: 2026-10-12
- Shared benchmarks: 10

## Summary

- They share 10 benchmarks with published results for both. gpt-oss-120b scores higher in 1 category and Qwen3.5 Plus in 3 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Qwen3.5 Plus leads 32.8 to 20.0.
- The biggest single-benchmark swing is Mystery Game Puzzles: 2% for gpt-oss-120b and 17% for Qwen3.5 Plus.
- gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $0.40 / $2.40 for Qwen3.5 Plus.
- Qwen3.5 Plus accepts more context: 1M tokens versus 131K.
- gpt-oss-120b has downloadable open weights; the other is API-only.

## Snapshot

| | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| Provider | OpenAI | Alibaba (Qwen) |
| Noometry Index | 36.3 | 42.9 |
| Rank | 217 | 106 |
| Context | 131K | 1M |
| Input $/M | $0.037 | $0.40 |
| Output $/M | $0.17 | $2.40 |
| Weights | Open | Proprietary |

## Coding

- gpt-oss-120b: 33.5 (#256)
- Qwen3.5 Plus: —

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| ALE-Bench | 575.62 | 621.92 |
| SWE-bench Verified (bash only) | 26% | — |
| Aider Polyglot | 41.8% | — |
| SciCode | 36% | — |
| WeirdML | 48.2% | — |
| LMArena Coding | 1380 | — |
| AlgoTune | 1.41 | — |

## Agentic & Tool Use

- gpt-oss-120b: 12.2 (#153)
- Qwen3.5 Plus: —

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| Vending-Bench 2 | -21.53 | 0.54 |
| Terminal-Bench | 18.7% | — |
| APEX-Agents | 4.4% | — |
| METR Time Horizons | 56.6% | — |

## Reasoning

- gpt-oss-120b: 20.0 (#245)
- Qwen3.5 Plus: 32.8 (#74)

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| Chess Puzzles | 20% | 22% |
| Mystery Game Puzzles | 2% | 17% |
| DTBench | 76.3% | 80.5% |
| LMCA | 22.1% | 36.4% |
| Epoch Capabilities Index | 139.93 | 146.78 |
| SimpleBench | 22.1% | — |
| Kagi LLM Benchmark | 58.6% | — |
| CritPt | 1.1% | — |
| LMArena Hard Prompts | 1364 | — |
| Surface Evolver Bench | 25% | — |

## Math

- gpt-oss-120b: 52.5 (#50)
- Qwen3.5 Plus: 49.6 (#61)

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 88.9% | 86.7% |
| Omni-MATH | 68.8% | — |
| LMArena Math | 1389 | — |
| FrontierMath (Feb 2025 set) | — | 21% |
| FrontierMath Tier 4 (v1) | — | 2.1% |

## Knowledge

- gpt-oss-120b: 42.4 (#96)
- Qwen3.5 Plus: 46.0 (#83)

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| GPQA Diamond | 75.8% | 84.8% |
| Vectara Hallucination Rate | 14.2% | 10.7% |
| SimpleQA Verified | — | 25.4% |
| MMLU-Pro | 79.5% | — |
| Confabulations | 15.7% | — |
| GPQA (HELM) | 68.4% | — |
| LMArena Expert | 1356 | — |

## Multilingual

- gpt-oss-120b: 48.0 (#147)
- Qwen3.5 Plus: —

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| LMArena Non-English | 1351 | — |
| 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)
- Qwen3.5 Plus: —

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| IFEval | 83.6% | — |
| LMArena Instruction Following | 1318 | — |

## Long Context

- gpt-oss-120b: 31.4 (#278)
- Qwen3.5 Plus: 43.0 (#113)

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| Fiction.LiveBench | 44.4% | — |
| CL-bench | — | 19.8% |
| CL-bench Life | — | 12.4% |
| LMArena Longer Query | 1319 | — |

## Writing & Preference

- gpt-oss-120b: 46.5 (#217)
- Qwen3.5 Plus: —

| Benchmark | gpt-oss-120b | Qwen3.5 Plus |
|---|---|---|
| LMArena Text | 1365 | — |
| LMArena Creative Writing | 1275 | — |
| Short-Story Creative Writing | 77.1% | — |
| EQ-Bench Creative Writing | 961 | — |
| WildBench | 84.5% | — |
| LMArena Multi-Turn | 1340 | — |

## FAQ

### Is gpt-oss-120b better than Qwen3.5 Plus?

Qwen3.5 Plus is the stronger model overall, scoring 42.9 to 36.3 on the Noometry Index. gpt-oss-120b costs 13× less per token, which makes it the better buy when Qwen3.5 Plus's lead doesn't matter for your workload.

### Which is cheaper, gpt-oss-120b or Qwen3.5 Plus?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; Qwen3.5 Plus lists at $0.40 and $2.40.

### Which has the bigger context window?

Qwen3.5 Plus does, with 1M tokens against 131K.

### How many benchmarks do gpt-oss-120b and Qwen3.5 Plus share?

10 benchmarks have published results for both models. gpt-oss-120b has 48 scored results on Noometry and Qwen3.5 Plus has 15.