# GPT-5.5 vs Kimi K2.5

> Side-by-side benchmark comparison for GPT-5.5 and Kimi K2.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-5-vs-kimi-k2-5
- Last updated: September 4, 2026

- Shared sourced benchmarks: 15
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick GPT-5.5 if you want the stronger benchmark profile. Kimi K2.5 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- GPT-5.5 leads overall 73.27 to 55.62.
- The clearest category separation is in knowledge, where the averages are 73.3 for GPT-5.5 and 53.1 for Kimi K2.5.
- The biggest single benchmark swing is MCP Atlas in Agentic, with scores of 75.3% and 29.5%.
- Kimi K2.5 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- GPT-5.5 also has the larger context window at 1M.

## Model Snapshot

| Property | GPT-5.5 | Kimi K2.5 |
|----------|----------|----------|
| Creator | OpenAI | Moonshot AI |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Non-Reasoning |
| Context | 1M | 256K |
| Overall Score | 73.27 | 55.62 |
| Benchmarks Covered | 38 | 45 |
| Pricing (input/output) | $5.00 / $30.00 | $0.60 / $3.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- GPT-5.5 public-lane score: 63.9 (Supported · #15/151)
- Kimi K2.5 public-lane score: 46 (Estimated · #90/151)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 82% | 50.8% | GPT-5.5 |
| CyberGym | 81.8% | Coming soon | Coming soon |
| BrowseComp | 84.4% | 60.6% | GPT-5.5 |
| OSWorld-Verified | 78.7% | Coming soon | Coming soon |
| MCP Atlas | 75.3% | 29.5% | GPT-5.5 |
| Toolathlon | 55.6% | 27.8% | GPT-5.5 |
| τ²-bench results | 98% | Coming soon | Coming soon |
| Gert Labs | 72.93% | 45.88% | GPT-5.5 |
| ResearchClawBench | 17.0% | 14.0% | GPT-5.5 |
| OSWorld 2.0 | 13.0% | Coming soon | Coming soon |
| JobBench | 42.7% | 8.7% | GPT-5.5 |
| ExploitGym | 13.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 76.4% | Coming soon | Coming soon |
| Claw-Eval | Coming soon | 52.3% | Coming soon |
| QwenClawBench | Coming soon | 54.3% | Coming soon |
| τ³-bench results | Coming soon | 65.7% | Coming soon |
| DeepSearchQA | Coming soon | 77.1% | Coming soon |
| DeepPlanning | Coming soon | 14.4% | Coming soon |
| MCP-Tasks | Coming soon | 59.1% | Coming soon |
| WideResearch | Coming soon | 72.7% | Coming soon |

### Coding

- Winner: Coming soon
- GPT-5.5 public-lane score: 67.7 (Supported · #8/183)
- Kimi K2.5 public-lane score: 51.5 (Estimated · #64/183)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 58.6% | 50.7% | GPT-5.5 |
| Terminal-Bench 2.0 | 82.0% | Coming soon | Coming soon |
| Vibe Code Bench | 69.85% | Coming soon | Coming soon |
| React Native Evals | 84.7% | 77.2% | GPT-5.5 |
| cursorBench31 | 59.2% | Coming soon | Coming soon |
| cursorBench32 | 58.4% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 43.0% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 85.3% | Coming soon | Coming soon |
| SWE-bench (Vals) | 82.6% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 76.8% | Coming soon |
| SWE-bench Verified* | Coming soon | 70.8% | Coming soon |
| LiveCodeBench v6 | Coming soon | 85.0% | Coming soon |
| SWE Multilingual | Coming soon | 73% | Coming soon |
| SWE-Rebench | Coming soon | 58.5% | Coming soon |
| SciCode | Coming soon | 48.7% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- GPT-5.5 public-lane score: 71.3 (#19/48)
- Kimi K2.5 public-lane score: 65.7 (#24/48)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 81.2% | 78.5% | GPT-5.5 |
| MMMU-Pro w/ Python | 83.2% | Coming soon | Coming soon |
| OfficeQA Pro | 54.1% | Coming soon | Coming soon |
| Video-MME | Coming soon | 87.4% | Coming soon |
| MMVU | Coming soon | 80.4% | Coming soon |
| VideoMMMU | Coming soon | 86.6% | Coming soon |

### Reasoning

- Winner: Coming soon
- GPT-5.5 public-lane score: 63.5 (#15/22)
- Kimi K2.5 public-lane score: 53.5 (Unranked · 3 rankable rows)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| MRCR v2 64K-128K | 83.1% | Coming soon | Coming soon |
| MRCR v2 128K-256K | 87.5% | Coming soon | Coming soon |
| ARC-AGI-2 | 85% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.4% | Coming soon | Coming soon |
| LongBench v2 | Coming soon | 61% | Coming soon |

### Knowledge

- Winner: Coming soon
- GPT-5.5 public-lane score: 73.3 (Supported · #7/181)
- Kimi K2.5 public-lane score: 53.1 (Estimated · #70/181)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 93.6% | 87.6% | GPT-5.5 |
| GPQA-D | 93.6% | 87.6% | GPT-5.5 |
| HLE | 52.2% | 30.1% | GPT-5.5 |
| HLE w/o tools | 41.4% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 93.2% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 88.1% | Coming soon | Coming soon |
| SuperGPQA | Coming soon | 69.2% | Coming soon |
| MMLU-Pro | Coming soon | 87.1% | Coming soon |
| MMLU-Pro (Arcee) | Coming soon | 87.1% | Coming soon |

### Instruction Following

- Winner: Coming soon
- GPT-5.5 public-lane score: 92.9 (#7/120)
- Kimi K2.5 public-lane score: 85.6 (#40/120)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 93.9% | Coming soon |

### Multilingual

- Winner: Coming soon
- GPT-5.5 public-lane score: Coming soon
- Kimi K2.5 public-lane score: 38.2 (#8/12)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | Coming soon | 82.3% | Coming soon |
| NOVA-63 | Coming soon | 56.0% | Coming soon |

### Mathematics

- Winner: Coming soon
- GPT-5.5 public-lane score: 69.6 (Unranked · 3 rankable rows)
- Kimi K2.5 public-lane score: 62.4 (#5/7)

| Benchmark | GPT-5.5 | Kimi K2.5 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 51.7% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 51.700% | 27.900% | GPT-5.5 |
| FrontierMath v2 (Tier 4) | 35.400% | 4.200% | GPT-5.5 |
| AIME 2025 | Coming soon | 96.1% | Coming soon |
| AIME26 | Coming soon | 95.8% | Coming soon |
| AIME25 (Arcee) | Coming soon | 96.3% | Coming soon |
| HMMT Feb 2025 | Coming soon | 95.4% | Coming soon |
| HMMT Nov 2025 | Coming soon | 91.1% | Coming soon |
| HMMT Feb 2026 | Coming soon | 87.1% | Coming soon |
| MMAnswerBench | Coming soon | 81.8% | Coming soon |

## FAQ

### Which is better overall, GPT-5.5 or Kimi K2.5?

GPT-5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between GPT-5.5 and Kimi K2.5?

The widest category gap is in knowledge, where the averages are 73.3 for GPT-5.5 and 53.1 for Kimi K2.5.

### How many benchmarks does GPT-5.5 cover on BenchLM?

GPT-5.5 currently has 38 sourced benchmark scores on BenchLM.

### How many benchmarks does Kimi K2.5 cover on BenchLM?

Kimi K2.5 currently has 45 sourced benchmark scores on BenchLM.

## Related Comparisons

- [GPT-5.5 vs GPT-5.5 Pro](/compare/gpt-5-5-vs-gpt-5-5-pro)
- [Kimi K2.5 vs GPT-5.5 Pro](/compare/gpt-5-5-pro-vs-kimi-k2-5)
- [GPT-5.5 vs Kimi K2.5 (Reasoning)](/compare/gpt-5-5-vs-kimi-k2-5-reasoning)
- [Kimi K2.5 vs Kimi K2.5 (Reasoning)](/compare/kimi-k2-5-vs-kimi-k2-5-reasoning)

## Explore More

- [GPT-5.5 profile](/models/gpt-5-5)
- [Kimi K2.5 profile](/models/kimi-k2-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)