Model comparison
Kimi K2 (Jul 2025) vs Kimi K2.5
Kimi K2.5 is the stronger model overall, scoring 47.8 to 40.9 on the Noometry Index.
Last verified . 30 shared benchmarks.
Summary
- They share 30 benchmarks with published results for both. Kimi K2 (Jul 2025) scores higher in 0 categories and Kimi K2.5 in 9 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Kimi K2.5 leads 53.6 to 36.9.
- The biggest single-benchmark swing is SimpleBench: 26.3% for Kimi K2 (Jul 2025) and 46.8% for Kimi K2.5.
- Kimi K2.5 is cheaper at $0.45 / $2.25 per million input/output tokens, against $0.57 / $2.30 for Kimi K2 (Jul 2025).
Side by side
| Kimi K2 (Jul 2025) | Kimi K2.5 | |
|---|---|---|
| Provider | Moonshot AI | Moonshot AI |
| Noometry Index | 40.9 | 47.8 |
| Released | 2025-07-12 | 2026-01-27 |
| Weights | Open | Open |
| Context window | 262K | 262K |
| Max output | 262K | 262K |
| Input $ / M tokens | $0.57 | $0.45 |
| Output $ / M tokens | $2.30 | $2.25 |
| Results tracked | 42 | 51 |
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Category by category
Coding Kimi K2.5 leads
Kimi K2 (Jul 2025): 43.1 (#83), Kimi K2.5: 48.7 (#48)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| SWE-bench Verified (bash only) | 63.4% | 70.8% |
| WeirdML | 42.8% | 45.6% |
| LMArena Coding | 1399 | 1474 |
| ALE-Bench | 597.5 | 821.65 |
| SWE-bench Verified | — | 73.8% |
| Aider Polyglot | 59.1% | — |
| LMArena WebDev | — | 1436 |
| SWE-bench Multilingual | — | 67.3% |
| SciCode | — | 49% |
| GSO | 4.9% | — |
Agentic & Tool Use Kimi K2.5 leads
Kimi K2 (Jul 2025): 32.2 (#59), Kimi K2.5: 34.0 (#44)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| Terminal-Bench | 35.7% | 43.2% |
| Berkeley Function Calling Leaderboard | 59.1% | — |
| OSWorld | — | 63.3% |
| METR Time Horizons | 59.2% | — |
| Vending-Bench 2 | — | 1,198 |
Reasoning Kimi K2.5 leads
Kimi K2 (Jul 2025): 22.7 (#173), Kimi K2.5: 31.2 (#74)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| SimpleBench | 26.3% | 46.8% |
| Kagi LLM Benchmark | 64.4% | 78.5% |
| LMArena Hard Prompts | 1384 | 1454 |
| Epoch Capabilities Index | 146.02 | 148.05 |
| ARC-AGI-2 | — | 11.8% |
| NYT Connections (extended) | — | 69.9% |
| ARC-AGI-1 | — | 65.3% |
| CritPt | — | 3.1% |
| Chess Puzzles | — | 12% |
| EnigmaEval | — | 3.4% |
| Thematic Generalization | — | 69.4% |
| ForecastBench | 60.2 | — |
Math Kimi K2.5 leads
Kimi K2 (Jul 2025): 40.1 (#81), Kimi K2.5: 50.3 (#46)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| LMArena Math | 1396 | 1470 |
| FrontierMath (Feb 2025 set) | 21.4% | 27.9% |
| FrontierMath Tier 4 (v1) | 0% | 4.2% |
| MathArena Final-Answer Competitions | — | 62.3% |
| OTIS Mock AIME 2024-2025 | — | 92.2% |
| Omni-MATH | 65.4% | — |
Knowledge Kimi K2.5 leads
Kimi K2 (Jul 2025): 36.9 (#153), Kimi K2.5: 53.6 (#52)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| Vectara Hallucination Rate | 17.9% | 14.2% |
| LMArena Expert | 1363 | 1466 |
| GPQA Diamond | — | 87.6% |
| Humanity's Last Exam | — | 24.4% |
| SimpleQA Verified | — | 34.3% |
| MMLU-Pro | 81.9% | — |
| Confabulations | 20.4% | — |
| GPQA (HELM) | 65.3% | — |
Multimodal Not comparable
Kimi K2 (Jul 2025): —, Kimi K2.5: 40.4 (#37)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| LMArena Vision | — | 1269 |
| LMArena Document | — | 1430 |
Multilingual Kimi K2.5 leads
Kimi K2 (Jul 2025): 49.8 (#125), Kimi K2.5: 54.1 (#50)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| LMArena Non-English | 1372 | 1433 |
| LMArena Chinese | 1416 | 1495 |
| LMArena French | 1379 | 1454 |
| LMArena German | 1386 | 1441 |
| LMArena Japanese | 1349 | 1422 |
| LMArena Korean | 1324 | 1412 |
| LMArena Russian | 1384 | 1436 |
| LMArena Spanish | 1383 | 1450 |
Instruction Following Kimi K2.5 leads
Kimi K2 (Jul 2025): 71.3 (#151), Kimi K2.5: 75.5 (#60)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| LMArena Instruction Following | 1347 | 1431 |
| IFEval | 85% | — |
Long Context Kimi K2.5 leads
Kimi K2 (Jul 2025): 41.2 (#140), Kimi K2.5: 52.1 (#7)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| Fiction.LiveBench | 66.7% | 86.1% |
| CL-bench | 17.6% | 19.3% |
| LMArena Longer Query | 1353 | 1445 |
| CL-bench Life | — | 13.2% |
Writing & Preference Kimi K2.5 leads
Kimi K2 (Jul 2025): 62.5 (#76), Kimi K2.5: 65.3 (#51)
| Benchmark | Kimi K2 (Jul 2025) | Kimi K2.5 |
|---|---|---|
| LMArena Text | 1380 | 1445 |
| LMArena Creative Writing | 1349 | 1423 |
| EQ-Bench Creative Writing | 1666 | 1579 |
| LMArena Multi-Turn | 1371 | 1444 |
| Short-Story Creative Writing | 85.6% | — |
| WildBench | 86.2% | — |
Frequently asked questions
Is Kimi K2 (Jul 2025) better than Kimi K2.5?
Kimi K2.5 is the stronger model overall, scoring 47.8 to 40.9 on the Noometry Index.
Which is cheaper, Kimi K2 (Jul 2025) 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; Kimi K2 (Jul 2025) lists at $0.57 and $2.30.
Is Kimi K2 (Jul 2025) or Kimi K2.5 better for coding?
Kimi K2.5 scores higher on coding benchmarks: 48.7 versus 43.1 in the Noometry coding category.
Which has the bigger context window?
Both accept 262K tokens.
How many benchmarks do Kimi K2 (Jul 2025) and Kimi K2.5 share?
30 benchmarks have published results for both models. Kimi K2 (Jul 2025) has 42 scored results on Noometry and Kimi K2.5 has 51.