# Claude Sonnet 5.5 vs Kimi K2.6

> Side-by-side benchmark comparison for Claude Sonnet 5.5 and Kimi K2.6 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-5-vs-kimi-2-6
- Last updated: September 28, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Sonnet 5.5 and Kimi K2.6 share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Kimi K2.6 has the lower published output-token price.
- Claude Sonnet 5.5 has the larger published context window at 1M.

## Model Snapshot

| Property | Claude Sonnet 5.5 | Kimi K2.6 |
|----------|----------|----------|
| Creator | Anthropic | Moonshot AI |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 256K |
| Independent public score (not head-to-head) | 80.49 | 59.22 |
| Benchmarks Covered | 47 | 37 |
| Pricing (input/output) | $2.00 / $10.00 | $0.95 / $4.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: 66.1 (Supported · #10/111)
- Kimi K2.6 public-lane score: 43.7 (Supported · #41/111)

| Benchmark | Claude Sonnet 5.5 | Kimi K2.6 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 70.60% | Coming soon | Coming soon |
| HLE w/ tools | 64.5% | Coming soon | Coming soon |
| DRACO | 87.0% | Coming soon | Coming soon |
| Terminal-Bench-Science 0.1 | 59.9% | Coming soon | Coming soon |
| LAB all-pass (Harvey held-out) | 10.0% | Coming soon | Coming soon |
| LAB criterion-pass (Harvey held-out) | 93.1% | Coming soon | Coming soon |
| Toolathlon Verified Pass@3 | 85.2% | Coming soon | Coming soon |
| Toolathlon Verified Pass³ | 68.5% | Coming soon | Coming soon |
| Toolathlon Verified avg. turns | 31.6 turns | Coming soon | Coming soon |
| AutomationBench (Zapier 1.0.6) | 44.7% | Coming soon | Coming soon |
| Toolathlon-Verified | 77.8% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 66.7% | Coming soon |
| BrowseComp | Coming soon | 83.2% | Coming soon |
| OSWorld-Verified | Coming soon | 73.1% | Coming soon |
| Toolathlon | Coming soon | 50% | Coming soon |
| MCP Atlas | Coming soon | 55.9% | Coming soon |
| Claw-Eval | Coming soon | 62.3% | Coming soon |
| DeepSearchQA | Coming soon | 92.5% | Coming soon |
| WideResearch | Coming soon | 80.8% | Coming soon |
| Gert Labs | Coming soon | 56.82% | Coming soon |
| ResearchClawBench | Coming soon | 18.0% | Coming soon |
| OSWorld 2.0 | Coming soon | 4.6% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 53.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: 79.6 (Estimated · #3/136)
- Kimi K2.6 public-lane score: 46.2 (Supported · #44/136)

| Benchmark | Claude Sonnet 5.5 | Kimi K2.6 | Winner |
|-----------|-----------|-----------|--------|
| FrontierCode 1.1 Main | 46.2% | Coming soon | Coming soon |
| cursorBench40 | 55.5% | Coming soon | Coming soon |
| SWE-bench Pro | 81.3% | 58.6% | Claude Sonnet 5.5 |
| SWE Multilingual | 90.3% | 76.7% | Claude Sonnet 5.5 |
| SWE Multimodal | 54.3% | Coming soon | Coming soon |
| DeepSWE | 71.0% | Coming soon | Coming soon |
| FrontierCode 1.1 Extended | 59.1% | Coming soon | Coming soon |
| ProgramBench | 79.7% | Coming soon | Coming soon |
| FrontierSWE v2 | 61.9% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 80.2% | Coming soon |
| LiveCodeBench v6 | Coming soon | 89.6% | Coming soon |
| SciCode | Coming soon | 52.2% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 66.7% | Coming soon |
| Vibe Code Bench | Coming soon | 37.89% | Coming soon |
| cursorBench31 | Coming soon | 47.6% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 86.8% | Coming soon |
| SWE-bench (Vals) | Coming soon | 76.2% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: 79.2 (#7/27)
- Kimi K2.6 public-lane score: Coming soon

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: 83.3 (Unranked · 7 rankable rows)
- Kimi K2.6 public-lane score: 64.9 (#27/50)

| Benchmark | Claude Sonnet 5.5 | Kimi K2.6 | Winner |
|-----------|-----------|-----------|--------|
| Chartography (no tools) | 61.6% | Coming soon | Coming soon |
| Chartography (tools) | 90.2% | Coming soon | Coming soon |
| BenchCAD Vision2Code (no tools) | 0.747 | Coming soon | Coming soon |
| BenchCAD Vision2Code (tools) | 0.963 | Coming soon | Coming soon |
| Biomedical image analysis | 72.2% | Coming soon | Coming soon |
| OfficeQA | 76.9% | Coming soon | Coming soon |
| OfficeQA Pro | 65.6% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 79.4% | Coming soon |
| MMMU-Pro w/ Python | Coming soon | 80.1% | Coming soon |
| CharXiv | Coming soon | 80.4% | Coming soon |
| MathVision | Coming soon | 87.4% | Coming soon |
| V* | Coming soon | 96.9% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: 80.9 (Supported · #6/160)
- Kimi K2.6 public-lane score: 59.1 (Supported · #37/160)

| Benchmark | Claude Sonnet 5.5 | Kimi K2.6 | Winner |
|-----------|-----------|-----------|--------|
| HealthBench (raw) | 69.4% | Coming soon | Coming soon |
| HealthBench (length-adjusted) | 65.4% | Coming soon | Coming soon |
| HealthBench Professional (raw) | 77.1% | Coming soon | Coming soon |
| HealthBench Professional | 69.2% | Coming soon | Coming soon |
| BioMysteryBench (human-solvable) | 89.2% | Coming soon | Coming soon |
| BioMysteryBench (human-difficult) | 44.7% | Coming soon | Coming soon |
| SpatialBench Verified | 72.5% | Coming soon | Coming soon |
| SingleCellBench | 59.1% | Coming soon | Coming soon |
| Protein Design | 51.0% | Coming soon | Coming soon |
| Morphology-to-molecule matching | 25.0% | Coming soon | Coming soon |
| Medicinal chemistry | 65.3% | Coming soon | Coming soon |
| Protein Design library ranking | 54.8% | Coming soon | Coming soon |
| De novo protein-binder design | 82.3% | Coming soon | Coming soon |
| Protocols (troubleshooting) | 67.3% | Coming soon | Coming soon |
| Protocols (understanding) | 66.6% | Coming soon | Coming soon |
| HLE w/o tools | 56.9% | Coming soon | Coming soon |
| GPQA | Coming soon | 90.5% | Coming soon |
| GPQA-D | Coming soon | 90.5% | Coming soon |
| HLE | Coming soon | 34.7% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 89.1% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 87.6% | Coming soon |

### Multilingual

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: Coming soon
- Kimi K2.6 public-lane score: Coming soon

| Benchmark | Claude Sonnet 5.5 | Kimi K2.6 | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | 92.1% | Coming soon | Coming soon |
| MILU | 91.6% | Coming soon | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Claude Sonnet 5.5 public-lane score: Coming soon
- Kimi K2.6 public-lane score: 71 (#1/7)

| Benchmark | Claude Sonnet 5.5 | Kimi K2.6 | Winner |
|-----------|-----------|-----------|--------|
| ArXivMath Aug. 2026 (no tools) | 86.8% | Coming soon | Coming soon |
| ArXivMath Aug. 2026 (tools) | 95.2% | Coming soon | Coming soon |
| AIME26 | Coming soon | 96.4% | Coming soon |
| HMMT Feb 2026 | Coming soon | 92.7% | Coming soon |
| MMAnswerBench | Coming soon | 86.0% | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 38.966% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 14.580% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Sonnet 5.5 and Kimi K2.6?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Claude Sonnet 5.5 vs GPT-6 Astra](/compare/claude-sonnet-5-5-vs-gpt-6-astra)
- [Kimi K2.6 vs GPT-6 Astra](/compare/gpt-6-astra-vs-kimi-2-6)
- [Claude Sonnet 5.5 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-claude-sonnet-5-5)
- [Kimi K2.6 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-kimi-2-6)

## Explore More

- [Claude Sonnet 5.5 profile](/models/claude-sonnet-5-5)
- [Kimi K2.6 profile](/models/kimi-2-6)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)