# GPT-OSS 120B vs Kimi K2

> Side-by-side benchmark comparison for GPT-OSS 120B and Kimi K2 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-oss-120b-vs-kimi-k2
- Last updated: October 17, 2026

- Shared sourced benchmarks: 6
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

GPT-OSS 120B leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- GPT-OSS 120B has the higher overall point estimate 37.32 to 33.48. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in instruction following, where the averages are 84.3 for GPT-OSS 120B and 48.4 for Kimi K2.
- The biggest single benchmark swing is AIME 2025 in Mathematics, with scores of 92.5% and 49.5%.
- GPT-OSS 120B is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | GPT-OSS 120B | Kimi K2 |
|----------|----------|----------|
| Creator | OpenAI | Moonshot AI |
| Type | Open Weight | Proprietary |
| Reasoning | Non-Reasoning | Non-Reasoning |
| Context | 128K | 128K |
| Overall Score | 37.32 | 33.48 |
| Benchmarks Covered | 8 | 13 |
| Pricing (input/output) | $0.00 / $0.00 | $0.60 / $2.50 |

## Category Breakdown

### Agentic

- Winner: Not comparable
- GPT-OSS 120B public-lane score: 19.5 (Estimated · #110/128)
- Kimi K2 public-lane score: Coming soon

| Benchmark | GPT-OSS 120B | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 29.61% | Coming soon | Coming soon |

### Coding

- Winner: Not comparable
- GPT-OSS 120B public-lane score: 23 (Estimated · #111/150)
- Kimi K2 public-lane score: Coming soon

| Benchmark | GPT-OSS 120B | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 62.4% | 65.8% | Kimi K2 |
| React Native Evals | 71.6% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 53.7% | Coming soon |
| SWE Multilingual | Coming soon | 47.3% | Coming soon |

### Reasoning

- Winner: Not comparable
- GPT-OSS 120B public-lane score: 61.6 (Unranked · 2 rankable rows)
- Kimi K2 public-lane score: 62.3 (Unranked · 2 rankable rows)

### Knowledge

- Winner: Directional only
- GPT-OSS 120B public-lane score: 38.6 (Supported · #122/184)
- Kimi K2 public-lane score: 36.1 (Estimated · #129/184)

| Benchmark | GPT-OSS 120B | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| MMLU | 90% | 89.5% | GPT-OSS 120B |
| GPQA | 80.1% | 75.1% | GPT-OSS 120B |
| HLE | 14.9% | 4.7% | GPT-OSS 120B |
| SuperGPQA | Coming soon | 57.2% | Coming soon |
| MMLU-Pro | Coming soon | 81.1% | Coming soon |
| SimpleQA | Coming soon | 31% | Coming soon |

### Instruction Following

- Winner: Directional only
- GPT-OSS 120B public-lane score: 84.3 (#50/148)
- Kimi K2 public-lane score: 48.4 (#96/148)

| Benchmark | GPT-OSS 120B | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 89.8% | Coming soon |

### Mathematics

- Winner: Not comparable
- GPT-OSS 120B public-lane score: Coming soon
- Kimi K2 public-lane score: 0 (#12/12)

| Benchmark | GPT-OSS 120B | Kimi K2 | Winner |
|-----------|-----------|-----------|--------|
| AIME 2024 | 95.8% | 69.6% | GPT-OSS 120B |
| AIME 2025 | 92.5% | 49.5% | GPT-OSS 120B |
| MATH-500 | Coming soon | 97.4% | Coming soon |

## FAQ

### Which is better overall, GPT-OSS 120B or Kimi K2?

GPT-OSS 120B has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between GPT-OSS 120B and Kimi K2?

The widest category gap is in instruction following, where the averages are 84.3 for GPT-OSS 120B and 48.4 for Kimi K2.

### How many benchmarks does GPT-OSS 120B cover on BenchLM?

GPT-OSS 120B currently has 8 sourced benchmark scores on BenchLM.

### How many benchmarks does Kimi K2 cover on BenchLM?

Kimi K2 currently has 13 sourced benchmark scores on BenchLM.

## Related Comparisons

- [GPT-OSS 120B vs GPT-OSS 20B](/compare/gpt-oss-120b-vs-gpt-oss-20b)
- [Kimi K2 vs GPT-OSS 20B](/compare/gpt-oss-20b-vs-kimi-k2)
- [GPT-OSS 120B vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-gpt-oss-120b)
- [Kimi K2 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-kimi-k2)

## Explore More

- [GPT-OSS 120B profile](/models/gpt-oss-120b)
- [Kimi K2 profile](/models/kimi-k2)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)