Model comparison
Kimi K2 (Jul 2025) vs Mistral Small 3.1
Kimi K2 (Jul 2025) is the stronger model overall, scoring 41.2 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 2.5× less per token, which makes it the better buy when Kimi K2 (Jul 2025)'s lead doesn't matter for your workload.
Last verified . 24 shared benchmarks.
Mistral AISummary
- They share 24 benchmarks with published results for both. Kimi K2 (Jul 2025) scores higher in 8 categories and Mistral Small 3.1 in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where Kimi K2 (Jul 2025) leads 42.7 to 14.7.
- The biggest single-benchmark swing is Omni-MATH: 65.4% for Kimi K2 (Jul 2025) and 24.8% for Mistral Small 3.1.
- Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $0.57 / $2.30 for Kimi K2 (Jul 2025).
- Kimi K2 (Jul 2025) accepts more context: 262K tokens versus 128K.
Side by side
| Kimi K2 (Jul 2025) | Mistral Small 3.1 | |
|---|---|---|
| Provider | Moonshot AI | Mistral AI |
| Noometry Index | 41.2 | 31.7 |
| Released | 2025-07-12 | 2025-03-17 |
| Weights | Open | Open |
| Context window | 262K | 128K |
| Max output | 262K | 102K |
| Input $ / M tokens | $0.57 | $0.35 |
| Output $ / M tokens | $2.30 | $0.56 |
| Results tracked | 42 | 28 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 42.4 (#102), Mistral Small 3.1: 38.3 (#179)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| LMArena Coding | 1399 | 1309 |
| SWE-bench Verified (bash only) | 63.4% | — |
| Aider Polyglot | 59.1% | — |
| GSO | 4.9% | — |
| WeirdML | 42.8% | — |
| ALE-Bench | 597.5 | — |
Agentic & Tool Use Not comparable
Kimi K2 (Jul 2025): 32.4 (#64), Mistral Small 3.1: —
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| Terminal-Bench | 35.7% | — |
| Berkeley Function Calling Leaderboard | 59.1% | — |
| METR Time Horizons | 59.2% | — |
Reasoning Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 23.3 (#179), Mistral Small 3.1: 19.7 (#254)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| LMArena Hard Prompts | 1384 | 1278 |
| Epoch Capabilities Index | 146.01 | 127.48 |
| SimpleBench | 26.3% | — |
| Kagi LLM Benchmark | 64.4% | — |
| Chess Puzzles | — | 1% |
| ForecastBench | 60.2 | — |
Math Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 42.7 (#83), Mistral Small 3.1: 14.7 (#301)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| Omni-MATH | 65.4% | 24.8% |
| LMArena Math | 1397 | 1262 |
| OTIS Mock AIME 2024-2025 | — | 3.9% |
| FrontierMath (Feb 2025 set) | 21.4% | — |
| FrontierMath Tier 4 (v1) | 0% | — |
Knowledge Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 37.3 (#157), Mistral Small 3.1: 22.6 (#271)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| MMLU-Pro | 81.9% | 61% |
| GPQA (HELM) | 65.3% | 39.2% |
| LMArena Expert | 1365 | 1257 |
| GPQA Diamond | — | 41.9% |
| Confabulations | 20.4% | — |
| Vectara Hallucination Rate | 17.9% | — |
Multimodal Not comparable
Kimi K2 (Jul 2025): —, Mistral Small 3.1: 33.2 (#99)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | — | 1136 |
Multilingual Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 49.6 (#130), Mistral Small 3.1: 41.2 (#209)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | 1372 | 1255 |
| LMArena Chinese | 1415 | 1253 |
| LMArena French | 1379 | 1273 |
| LMArena German | 1387 | 1266 |
| LMArena Japanese | 1349 | 1208 |
| LMArena Korean | 1325 | 1206 |
| LMArena Russian | 1385 | 1263 |
| LMArena Spanish | 1386 | 1283 |
Instruction Following Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 71.1 (#156), Mistral Small 3.1: 63.6 (#230)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| IFEval | 85% | 75% |
| LMArena Instruction Following | 1348 | 1264 |
Long Context Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 41.2 (#145), Mistral Small 3.1: 39.5 (#178)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | 1353 | 1299 |
| Fiction.LiveBench | 66.7% | — |
| CL-bench | 17.6% | — |
Writing & Preference Kimi K2 (Jul 2025) leads
Kimi K2 (Jul 2025): 62.3 (#78), Mistral Small 3.1: 37.0 (#259)
| Benchmark | Kimi K2 (Jul 2025) | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | 1380 | 1277 |
| LMArena Creative Writing | 1350 | 1253 |
| EQ-Bench Creative Writing | 1666 | 761 |
| WildBench | 86.2% | 78.8% |
| LMArena Multi-Turn | 1371 | 1270 |
| Short-Story Creative Writing | 85.6% | — |
Frequently asked questions
Is Kimi K2 (Jul 2025) better than Mistral Small 3.1?
Kimi K2 (Jul 2025) is the stronger model overall, scoring 41.2 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 2.5× less per token, which makes it the better buy when Kimi K2 (Jul 2025)'s lead doesn't matter for your workload.
Which is cheaper, Kimi K2 (Jul 2025) or Mistral Small 3.1?
Mistral Small 3.1 is cheaper. It lists at $0.35 per million input tokens and $0.56 per million output tokens; Kimi K2 (Jul 2025) lists at $0.57 and $2.30.
Is Kimi K2 (Jul 2025) or Mistral Small 3.1 better for coding?
Kimi K2 (Jul 2025) scores higher on coding benchmarks: 42.4 versus 38.3 in the Noometry coding category.
Which has the bigger context window?
Kimi K2 (Jul 2025) does, with 262K tokens against 128K.
How many benchmarks do Kimi K2 (Jul 2025) and Mistral Small 3.1 share?
24 benchmarks have published results for both models. Kimi K2 (Jul 2025) has 42 scored results on Noometry and Mistral Small 3.1 has 28.