# GPT-5.5 vs Kimi K3

> Side-by-side benchmark comparison for GPT-5.5 and Kimi K3 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-5-vs-kimi-k3
- Last updated: September 10, 2026

- Shared sourced benchmarks: 18
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Kimi K3 if you want the stronger benchmark profile. GPT-5.5 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Kimi K3 leads overall 74.82 to 72.07.
- The clearest category separation is in multimodal & grounded, where the averages are 71.3 for GPT-5.5 and 89.5 for Kimi K3.
- The biggest single benchmark swing is SWE-bench (Vals) in Coding, with scores of 82.6% and 93.4%.
- Kimi K3 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Kimi K3 also has the larger context window at 1.05M.

## Model Snapshot

| Property | GPT-5.5 | Kimi K3 |
|----------|----------|----------|
| Creator | OpenAI | Moonshot AI |
| Type | Proprietary | Pending |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1.05M |
| Overall Score | 72.07 | 74.82 |
| Benchmarks Covered | 39 | 44 |
| Pricing (input/output) | $5.00 / $30.00 | $3.00 / $15.00 |

## Category Breakdown

### Agentic

- Winner: Kimi K3
- GPT-5.5 public-lane score: 61 (Supported · #17/152)
- Kimi K3 public-lane score: 71.9 (Supported · #4/152)

| Benchmark | GPT-5.5 | Kimi K3 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 82% | 88.3% | Kimi K3 |
| CyberGym | 81.8% | Coming soon | Coming soon |
| BrowseComp | 84.4% | 91.2% | Kimi K3 |
| OSWorld-Verified | 78.7% | Coming soon | Coming soon |
| MCP Atlas | 75.3% | 84.2% | Kimi K3 |
| Toolathlon | 55.6% | Coming soon | Coming soon |
| τ²-bench results | 98% | Coming soon | Coming soon |
| Gert Labs | 72.93% | Coming soon | Coming soon |
| ResearchClawBench | 17.0% | Coming soon | Coming soon |
| OSWorld 2.0 | 13.0% | Coming soon | Coming soon |
| JobBench | 42.7% | 52.9% | Kimi K3 |
| ExploitGym | 13.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 76.4% | 80.9% | Kimi K3 |
| ApprenticeBench | 20% | 18% | GPT-5.5 |
| DeepSearchQA | Coming soon | 95.0% | Coming soon |
| Toolathlon-Verified | Coming soon | 73.2% | Coming soon |
| AutomationBench | Coming soon | 30.8% | Coming soon |
| APEX-Agents | Coming soon | 37.6% | Coming soon |
| SpreadsheetBench 2 | Coming soon | 34.8% | Coming soon |
| DECK-Bench | Coming soon | 73.5% | Coming soon |

### Coding

- Winner: Tie
- GPT-5.5 public-lane score: 67.6 (Supported · #7/151)
- Kimi K3 public-lane score: 68 (Supported · #6/151)

| Benchmark | GPT-5.5 | Kimi K3 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 58.6% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 82.0% | Coming soon | Coming soon |
| Vibe Code Bench | 69.85% | Coming soon | Coming soon |
| React Native Evals | 84.7% | Coming soon | Coming soon |
| cursorBench31 | 59.2% | Coming soon | Coming soon |
| cursorBench32 | 58.4% | 60.8% | Kimi K3 |
| FrontierCode 1.1 Main | 43.0% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 85.3% | 87.2% | Kimi K3 |
| SWE-bench (Vals) | 82.6% | 93.4% | Kimi K3 |
| DeepSWE | Coming soon | 67.5% | Coming soon |
| FrontierSWE | Coming soon | 81.2% | Coming soon |
| ProgramBench | Coming soon | 77.8% | Coming soon |
| Kimi Code Bench v2 | Coming soon | 72.9% | Coming soon |
| sweMarathon | Coming soon | 42% | Coming soon |
| PostTrain Bench | Coming soon | 36.6% | Coming soon |
| MLS-Bench Lite | Coming soon | 48.3% | Coming soon |
| VulcanBench v3 | Coming soon | 73.7% | Coming soon |
| OpenHarmony Bench | Coming soon | 57.3% | Coming soon |
| FrontierSWE v2 | Coming soon | 25.9% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- GPT-5.5 public-lane score: 71.3 (#19/48)
- Kimi K3 public-lane score: 89.5 (#1/48)

| Benchmark | GPT-5.5 | Kimi K3 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 81.2% | 81.6% | Kimi K3 |
| MMMU-Pro w/ Python | 83.2% | 83.4% | Kimi K3 |
| OfficeQA Pro | 54.1% | 63.3% | Kimi K3 |
| CharXiv w/o tools | Coming soon | 84.8% | Coming soon |
| CharXiv | Coming soon | 91.3% | Coming soon |
| MathVision | Coming soon | 94.3% | Coming soon |
| MathVision w/ Python | Coming soon | 97.8% | Coming soon |
| BabyVision w/ Python | Coming soon | 85.7% | Coming soon |
| ZeroBench | Coming soon | 23.0% | Coming soon |
| ZeroBench w/ Python | Coming soon | 41.0% | Coming soon |
| WorldVQA ForceAnswer | Coming soon | 51.0% | Coming soon |
| OmniDocBench | Coming soon | 91.1% | Coming soon |
| PerceptionBench | Coming soon | 58.5% | Coming soon |

### Reasoning

- Winner: Coming soon
- GPT-5.5 public-lane score: 64 (#13/20)
- Kimi K3 public-lane score: 78.5 (#3/20)

| Benchmark | GPT-5.5 | Kimi K3 | 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 |

### Knowledge

- Winner: GPT-5.5
- GPT-5.5 public-lane score: 72.9 (Supported · #7/183)
- Kimi K3 public-lane score: 72 (Supported · #8/183)

| Benchmark | GPT-5.5 | Kimi K3 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 93.6% | 93.5% | GPT-5.5 |
| GPQA-D | 93.6% | 93.5% | GPT-5.5 |
| HLE | 52.2% | 56% | Kimi K3 |
| HLE w/o tools | 41.4% | 43.5% | Kimi K3 |
| GPQA Diamond (Vals) | 93.2% | 92.9% | GPT-5.5 |
| MMLU-Pro (Vals) | 88.1% | 88.0% | GPT-5.5 |

### Instruction Following

- Winner: Coming soon
- GPT-5.5 public-lane score: 93.2 (#7/123)
- Kimi K3 public-lane score: Coming soon

### Mathematics

- Winner: Coming soon
- GPT-5.5 public-lane score: 69.6 (Unranked · 3 rankable rows)
- Kimi K3 public-lane score: Coming soon

| Benchmark | GPT-5.5 | Kimi K3 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 51.7% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 51.700% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 35.400% | Coming soon | Coming soon |

## FAQ

### Which is better overall, GPT-5.5 or Kimi K3?

Kimi K3 is ahead overall on BenchLM right now.

### Where is the biggest gap between GPT-5.5 and Kimi K3?

The widest category gap is in multimodal & grounded, where the averages are 71.3 for GPT-5.5 and 89.5 for Kimi K3.

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

GPT-5.5 currently has 39 sourced benchmark scores on BenchLM.

### How many benchmarks does Kimi K3 cover on BenchLM?

Kimi K3 currently has 44 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 K3 vs GPT-5.5 Pro](/compare/gpt-5-5-pro-vs-kimi-k3)
- [GPT-5.5 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-gpt-5-5)
- [Kimi K3 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-kimi-k3)

## Explore More

- [GPT-5.5 profile](/models/gpt-5-5)
- [Kimi K3 profile](/models/kimi-k3)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)