Model comparison
Claude Opus 4.1 vs Kimi K2.5
Kimi K2.5 is the stronger model overall, scoring 48.1 to 41.0 on the Noometry Index.
Last verified . 32 shared benchmarks.
Summary
- They share 32 benchmarks with published results for both. Claude Opus 4.1 scores higher in 3 categories and Kimi K2.5 in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where Kimi K2.5 leads 51.8 to 22.3.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 68.9% for Claude Opus 4.1 and 92.2% for Kimi K2.5.
- Kimi K2.5 is cheaper at $0.45 / $2.25 per million input/output tokens, against $15 / $75 for Claude Opus 4.1.
- Kimi K2.5 accepts more context: 262K tokens versus 200K.
- Kimi K2.5 has downloadable open weights; the other is API-only.
Side by side
| Claude Opus 4.1 | Kimi K2.5 | |
|---|---|---|
| Provider | Anthropic | Moonshot AI |
| Noometry Index | 41.0 | 48.1 |
| Released | 2025-08-05 | 2026-01-27 |
| Weights | Proprietary | Open |
| Context window | 200K | 262K |
| Max output | 32K | 262K |
| Input $ / M tokens | $15 | $0.45 |
| Output $ / M tokens | $75 | $2.25 |
| Results tracked | 48 | 51 |
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Category by category
Coding Kimi K2.5 leads
Claude Opus 4.1: 44.4 (#73), Kimi K2.5: 48.8 (#53)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| SWE-bench Verified | 73.3% | 73.8% |
| LMArena WebDev | 1390 | 1437 |
| WeirdML | 45.9% | 45.6% |
| LMArena Coding | 1479 | 1474 |
| ALE-Bench | 674.77 | 821.65 |
| SWE-bench Verified (bash only) | — | 70.8% |
| SWE-bench Multilingual | — | 67.3% |
| SciCode | — | 49% |
| AlgoTune | 1.34 | — |
Agentic & Tool Use Too close to call
Claude Opus 4.1: 35.0 (#41), Kimi K2.5: 34.2 (#48)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| Terminal-Bench | 38% | 43.2% |
| GDPval | 43.6% | — |
| Cybench | 42% | — |
| DeepResearch Bench | 48.3% | — |
| OSWorld | — | 63.3% |
| LMArena Search | 1148 | — |
| METR Time Horizons | 66.8% | — |
| Vending-Bench 2 | — | 1,198 |
Reasoning Claude Opus 4.1 leads
Claude Opus 4.1: 32.2 (#76), Kimi K2.5: 31.2 (#80)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| SimpleBench | 60% | 46.8% |
| Chess Puzzles | 7% | 12% |
| EnigmaEval | 7.2% | 3.4% |
| LMArena Hard Prompts | 1443 | 1453 |
| Epoch Capabilities Index | 144.12 | 148.03 |
| ARC-AGI-2 | — | 11.8% |
| Kagi LLM Benchmark | — | 78.5% |
| NYT Connections (extended) | — | 69.9% |
| ARC-AGI-1 | — | 65.3% |
| CritPt | — | 3.1% |
| Thematic Generalization | — | 69.4% |
| EBR-Bench | 7.9% | — |
| Mystery Game Puzzles | 21% | — |
| DTBench | 80% | — |
| LMCA | 37.1% | — |
| ForecastBench | 62 | — |
Math Kimi K2.5 leads
Claude Opus 4.1: 22.3 (#277), Kimi K2.5: 51.8 (#53)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 68.9% | 92.2% |
| LMArena Math | 1431 | 1470 |
| FrontierMath (Feb 2025 set) | 7.2% | 27.9% |
| FrontierMath Tier 4 (v1) | 4.2% | 4.2% |
| FrontierMath (Tiers 1-3) | 12.6% | — |
| FrontierMath Tier 4 | 2.4% | — |
| MathArena Final-Answer Competitions | — | 62.3% |
Knowledge Kimi K2.5 leads
Claude Opus 4.1: 42.0 (#101), Kimi K2.5: 53.6 (#56)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| GPQA Diamond | 77.3% | 87.6% |
| Humanity's Last Exam | 11.5% | 24.4% |
| Vectara Hallucination Rate | 11.8% | 14.2% |
| LMArena Expert | 1439 | 1466 |
| SimpleQA Verified | — | 34.3% |
| Confabulations | 17.1% | — |
Multimodal Kimi K2.5 leads
Claude Opus 4.1: 26.8 (#119), Kimi K2.5: 41.1 (#39)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Vision | — | 1269 |
| VPCT | 35% | — |
| LMArena Document | — | 1430 |
Multilingual Kimi K2.5 leads
Claude Opus 4.1: 52.0 (#95), Kimi K2.5: 53.9 (#53)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Non-English | 1405 | 1433 |
| LMArena Chinese | 1427 | 1495 |
| LMArena French | 1431 | 1454 |
| LMArena German | 1413 | 1441 |
| LMArena Japanese | 1378 | 1421 |
| LMArena Korean | 1380 | 1410 |
| LMArena Russian | 1422 | 1435 |
| LMArena Spanish | 1448 | 1450 |
Instruction Following Too close to call
Claude Opus 4.1: 75.6 (#58), Kimi K2.5: 75.3 (#64)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Instruction Following | 1435 | 1431 |
Long Context Kimi K2.5 leads
Claude Opus 4.1: 44.5 (#63), Kimi K2.5: 52.1 (#7)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Longer Query | 1455 | 1445 |
| Fiction.LiveBench | — | 86.1% |
| CL-bench | — | 19.3% |
| CL-bench Life | — | 13.2% |
Writing & Preference Kimi K2.5 leads
Claude Opus 4.1: 62.4 (#74), Kimi K2.5: 65.1 (#53)
| Benchmark | Claude Opus 4.1 | Kimi K2.5 |
|---|---|---|
| LMArena Text | 1419 | 1445 |
| LMArena Creative Writing | 1412 | 1423 |
| LMArena Multi-Turn | 1444 | 1444 |
| Short-Story Creative Writing | 84.7% | — |
| EQ-Bench Creative Writing | — | 1579 |
Frequently asked questions
Is Claude Opus 4.1 better than Kimi K2.5?
Kimi K2.5 is the stronger model overall, scoring 48.1 to 41.0 on the Noometry Index.
Which is cheaper, Claude Opus 4.1 or Kimi K2.5?
Kimi K2.5 is cheaper. It lists at $0.45 per million input tokens and $2.25 per million output tokens; Claude Opus 4.1 lists at $15 and $75.
Is Claude Opus 4.1 or Kimi K2.5 better for coding?
Kimi K2.5 scores higher on coding benchmarks: 48.8 versus 44.4 in the Noometry coding category.
Which has the bigger context window?
Kimi K2.5 does, with 262K tokens against 200K.
How many benchmarks do Claude Opus 4.1 and Kimi K2.5 share?
32 benchmarks have published results for both models. Claude Opus 4.1 has 48 scored results on Noometry and Kimi K2.5 has 51.