Model comparison
Claude Sonnet 5.5 vs Kimi K2 Thinking Turbo
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 45.8 on the Noometry Index.
Last verified . 15 shared benchmarks.
Summary
- They share 15 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 8 categories and Kimi K2 Thinking Turbo in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 47.4.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Sonnet 5.5 and 83.1% for Kimi K2 Thinking Turbo.
- Kimi K2 Thinking Turbo has downloadable open weights; the other is API-only.
Side by side
| Claude Sonnet 5.5 | Kimi K2 Thinking Turbo | |
|---|---|---|
| Provider | Anthropic | Moonshot AI |
| Noometry Index | 61.9 | 45.8 |
| Released | 2026-09-28 | 2025-11-06 |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $2 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 32 | 21 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 67.3 (#6), Kimi K2 Thinking Turbo: 38.4 (#178)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena WebDev | 1774 | 1322 |
| LMArena Coding | 1513 | 1454 |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| ALE-Bench | 1,819 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 5.5: 45.0 (#16), Kimi K2 Thinking Turbo: —
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| APEX-Agents | 75.5% | — |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 54.0 (#28), Kimi K2 Thinking Turbo: 32.5 (#75)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Hard Prompts | 1495 | 1428 |
| NYT Connections (extended) | 80.5% | — |
| CritPt | 31.4% | — |
| Chess Puzzles | — | 20% |
| Mystery Game Puzzles | 65% | — |
| Epoch Capabilities Index | 165.03 | — |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 87.9 (#6), Kimi K2 Thinking Turbo: 47.4 (#68)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 83.1% |
| LMArena Math | 1510 | 1429 |
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| ProofBench | 100% | — |
| FrontierMath Erdős | 2.9% | — |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#12), Kimi K2 Thinking Turbo: 50.9 (#69)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| GPQA Diamond | 95.6% | 84.2% |
| LMArena Expert | 1540 | 1439 |
| SimpleQA Verified | 46.5% | — |
Multimodal Not comparable
Claude Sonnet 5.5: 51.5 (#6), Kimi K2 Thinking Turbo: —
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Vision | 1289 | — |
| Furniture Assembly | 75% | — |
Multilingual Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 55.3 (#30), Kimi K2 Thinking Turbo: 51.4 (#109)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Non-English | 1452 | 1398 |
| LMArena Chinese | 1522 | 1456 |
| LMArena Russian | 1451 | 1391 |
| LMArena French | — | 1425 |
| LMArena German | — | 1390 |
| LMArena Japanese | — | 1357 |
| LMArena Korean | — | 1330 |
| LMArena Spanish | — | 1406 |
Instruction Following Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 78.3 (#11), Kimi K2 Thinking Turbo: 74.0 (#109)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Instruction Following | 1495 | 1403 |
Long Context Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.9 (#28), Kimi K2 Thinking Turbo: 43.2 (#102)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Longer Query | 1498 | 1415 |
Writing & Preference Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#40), Kimi K2 Thinking Turbo: 60.0 (#104)
| Benchmark | Claude Sonnet 5.5 | Kimi K2 Thinking Turbo |
|---|---|---|
| LMArena Text | 1471 | 1415 |
| LMArena Creative Writing | 1465 | 1374 |
| LMArena Multi-Turn | 1474 | 1414 |
Frequently asked questions
Is Claude Sonnet 5.5 better than Kimi K2 Thinking Turbo?
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 45.8 on the Noometry Index.
Is Claude Sonnet 5.5 or Kimi K2 Thinking Turbo better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 38.4 in the Noometry coding category.
How many benchmarks do Claude Sonnet 5.5 and Kimi K2 Thinking Turbo share?
15 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Kimi K2 Thinking Turbo has 21.