Model comparison
Kimi K2 (Jul 2025) vs o4-mini
Kimi K2 (Jul 2025) and o4-mini score almost the same on the Noometry Index (41.2 vs 41.6), so choose on price, context window or the category you care about most.
Last verified . 39 shared benchmarks.
Summary
- They share 39 benchmarks with published results for both. Kimi K2 (Jul 2025) scores higher in 4 categories and o4-mini in 5 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Kimi K2 (Jul 2025) leads 62.3 to 54.0.
- The biggest single-benchmark swing is SWE-bench Verified (bash only): 63.4% for Kimi K2 (Jul 2025) and 45% for o4-mini.
- Kimi K2 (Jul 2025) is cheaper at $0.57 / $2.30 per million input/output tokens, against $1.10 / $4.40 for o4-mini.
- Kimi K2 (Jul 2025) accepts more context: 262K tokens versus 200K.
- Kimi K2 (Jul 2025) has downloadable open weights; the other is API-only.
Side by side
| Kimi K2 (Jul 2025) | o4-mini | |
|---|---|---|
| Provider | Moonshot AI | OpenAI |
| Noometry Index | 41.2 | 41.6 |
| Released | 2025-07-12 | 2025-04-16 |
| Weights | Open | Proprietary |
| Context window | 262K | 200K |
| Max output | 262K | 100K |
| Input $ / M tokens | $0.57 | $1.10 |
| Output $ / M tokens | $2.30 | $4.40 |
| Results tracked | 42 | 60 |
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Category by category
Coding Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 42.4 (#102), o4-mini: 40.9 (#127)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| SWE-bench Verified (bash only) | 63.4% | 45% |
| Aider Polyglot | 59.1% | 72% |
| GSO | 4.9% | 3.6% |
| WeirdML | 42.8% | 52.6% |
| LMArena Coding | 1399 | 1368 |
| ALE-Bench | 597.5 | 826.17 |
| CadEval | — | 62% |
| AlgoTune | — | 1.72 |
Agentic & Tool Use Too close to call
Kimi K2 (Jul 2025): 32.4 (#64), o4-mini: 32.6 (#61)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| Berkeley Function Calling Leaderboard | 59.1% | 53.2% |
| METR Time Horizons | 59.2% | 63.9% |
| Terminal-Bench | 35.7% | — |
| GDPval | — | 25.3% |
Reasoning o4-mini leads
Kimi K2 (Jul 2025): 23.3 (#179), o4-mini: 24.6 (#162)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| SimpleBench | 26.3% | 38.7% |
| Kagi LLM Benchmark | 64.4% | 67.6% |
| LMArena Hard Prompts | 1384 | 1351 |
| Epoch Capabilities Index | 146.01 | 145.64 |
| ForecastBench | 60.2 | 61.8 |
| ARC-AGI-2 | — | 6.1% |
| ARC-AGI-1 | — | 58.7% |
| CritPt | — | 0.6% |
| Chess Puzzles | — | 26% |
| EnigmaEval | — | 9.2% |
| Mystery Game Puzzles | — | 5% |
| DTBench | — | 77.6% |
| LMCA | — | 26.5% |
Math Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 42.7 (#83), o4-mini: 40.8 (#89)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| Omni-MATH | 65.4% | 72% |
| LMArena Math | 1397 | 1389 |
| FrontierMath (Feb 2025 set) | 21.4% | 24.8% |
| FrontierMath Tier 4 (v1) | 0% | 6.3% |
| FrontierMath (Tiers 1-3) | — | 36.1% |
| FrontierMath Tier 4 | — | 4.9% |
| OTIS Mock AIME 2024-2025 | — | 81.7% |
| MATH Level 5 | — | 97.8% |
Knowledge o4-mini leads
Kimi K2 (Jul 2025): 37.3 (#157), o4-mini: 43.6 (#91)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| MMLU-Pro | 81.9% | 82% |
| Confabulations | 20.4% | 15.8% |
| Vectara Hallucination Rate | 17.9% | 18.6% |
| GPQA (HELM) | 65.3% | 73.5% |
| LMArena Expert | 1365 | 1343 |
| GPQA Diamond | — | 79.6% |
| Humanity's Last Exam | — | 18.1% |
| SimpleQA Verified | — | 19.6% |
Multimodal Not comparable
Kimi K2 (Jul 2025): —, o4-mini: 40.2 (#49)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| LMArena Vision | — | 1194 |
| GeoBench | — | 64% |
| VPCT | — | 57.5% |
Multilingual Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 49.6 (#130), o4-mini: 47.0 (#154)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| LMArena Non-English | 1372 | 1337 |
| LMArena Chinese | 1415 | 1354 |
| LMArena French | 1379 | 1364 |
| LMArena German | 1387 | 1336 |
| LMArena Japanese | 1349 | 1308 |
| LMArena Korean | 1325 | 1312 |
| LMArena Russian | 1385 | 1334 |
| LMArena Spanish | 1386 | 1347 |
Instruction Following o4-mini leads
Kimi K2 (Jul 2025): 71.1 (#156), o4-mini: 75.2 (#68)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| IFEval | 85% | 92.8% |
| LMArena Instruction Following | 1348 | 1321 |
Long Context o4-mini leads
Kimi K2 (Jul 2025): 41.2 (#145), o4-mini: 45.5 (#33)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| Fiction.LiveBench | 66.7% | 77.8% |
| LMArena Longer Query | 1353 | 1315 |
| CL-bench | 17.6% | — |
Writing & Preference Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 62.3 (#78), o4-mini: 54.0 (#152)
| Benchmark | Kimi K2 (Jul 2025) | o4-mini |
|---|---|---|
| LMArena Text | 1380 | 1353 |
| LMArena Creative Writing | 1350 | 1294 |
| Short-Story Creative Writing | 85.6% | 75% |
| WildBench | 86.2% | 85.4% |
| LMArena Multi-Turn | 1371 | 1350 |
| EQ-Bench Creative Writing | 1666 | — |
Frequently asked questions
Is Kimi K2 (Jul 2025) better than o4-mini?
Kimi K2 (Jul 2025) and o4-mini score almost the same on the Noometry Index (41.2 vs 41.6), so choose on price, context window or the category you care about most.
Which is cheaper, Kimi K2 (Jul 2025) or o4-mini?
Kimi K2 (Jul 2025) is cheaper. It lists at $0.57 per million input tokens and $2.30 per million output tokens; o4-mini lists at $1.10 and $4.40.
Is Kimi K2 (Jul 2025) or o4-mini better for coding?
Kimi K2 (Jul 2025) scores higher on coding benchmarks: 42.4 versus 40.9 in the Noometry coding category.
Which has the bigger context window?
Kimi K2 (Jul 2025) does, with 262K tokens against 200K.
How many benchmarks do Kimi K2 (Jul 2025) and o4-mini share?
39 benchmarks have published results for both models. Kimi K2 (Jul 2025) has 42 scored results on Noometry and o4-mini has 60.