Model comparison
Kimi K2.5 vs Mistral Small 3.1
Kimi K2.5 is the stronger model overall, scoring 47.8 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 2.2× less per token, which makes it the better buy when Kimi K2.5's lead doesn't matter for your workload.
Last verified . 23 shared benchmarks.
Mistral AISummary
- They share 23 benchmarks with published results for both. Kimi K2.5 scores higher in 9 categories and Mistral Small 3.1 in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Kimi K2.5 leads 50.3 to 13.7.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 92.2% for Kimi K2.5 and 3.9% for Mistral Small 3.1.
- Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $0.45 / $2.25 for Kimi K2.5.
- Kimi K2.5 accepts more context: 262K tokens versus 128K.
Side by side
| Kimi K2.5 | Mistral Small 3.1 | |
|---|---|---|
| Provider | Moonshot AI | Mistral AI |
| Noometry Index | 47.8 | 31.4 |
| Released | 2026-01-27 | 2025-03-17 |
| Weights | Open | Open |
| Context window | 262K | 128K |
| Max output | 262K | 102K |
| Input $ / M tokens | $0.45 | $0.35 |
| Output $ / M tokens | $2.25 | $0.56 |
| Results tracked | 51 | 28 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Kimi K2.5 leads
Kimi K2.5: 48.7 (#48), Mistral Small 3.1: 37.7 (#175)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Coding | 1474 | 1309 |
| SWE-bench Verified | 73.8% | — |
| SWE-bench Verified (bash only) | 70.8% | — |
| LMArena WebDev | 1436 | — |
| SWE-bench Multilingual | 67.3% | — |
| SciCode | 49% | — |
| WeirdML | 45.6% | — |
| ALE-Bench | 821.65 | — |
Agentic & Tool Use Not comparable
Kimi K2.5: 34.0 (#44), Mistral Small 3.1: —
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| Terminal-Bench | 43.2% | — |
| OSWorld | 63.3% | — |
| Vending-Bench 2 | 1,198 | — |
Reasoning Kimi K2.5 leads
Kimi K2.5: 31.2 (#74), Mistral Small 3.1: 18.9 (#249)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| Chess Puzzles | 12% | 1% |
| LMArena Hard Prompts | 1454 | 1278 |
| Epoch Capabilities Index | 148.05 | 127.48 |
| ARC-AGI-2 | 11.8% | — |
| SimpleBench | 46.8% | — |
| Kagi LLM Benchmark | 78.5% | — |
| NYT Connections (extended) | 69.9% | — |
| ARC-AGI-1 | 65.3% | — |
| CritPt | 3.1% | — |
| EnigmaEval | 3.4% | — |
| Thematic Generalization | 69.4% | — |
Math Kimi K2.5 leads
Kimi K2.5: 50.3 (#46), Mistral Small 3.1: 13.7 (#295)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 92.2% | 3.9% |
| LMArena Math | 1470 | 1261 |
| MathArena Final-Answer Competitions | 62.3% | — |
| Omni-MATH | — | 24.8% |
| FrontierMath (Feb 2025 set) | 27.9% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Kimi K2.5 leads
Kimi K2.5: 53.6 (#52), Mistral Small 3.1: 22.6 (#266)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| GPQA Diamond | 87.6% | 41.9% |
| LMArena Expert | 1466 | 1258 |
| Humanity's Last Exam | 24.4% | — |
| SimpleQA Verified | 34.3% | — |
| MMLU-Pro | — | 61% |
| Vectara Hallucination Rate | 14.2% | — |
| GPQA (HELM) | — | 39.2% |
Multimodal Kimi K2.5 leads
Kimi K2.5: 40.4 (#37), Mistral Small 3.1: 32.6 (#93)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Vision | 1269 | 1136 |
| LMArena Document | 1430 | — |
Multilingual Kimi K2.5 leads
Kimi K2.5: 54.1 (#50), Mistral Small 3.1: 41.4 (#204)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Non-English | 1433 | 1255 |
| LMArena Chinese | 1495 | 1254 |
| LMArena French | 1454 | 1270 |
| LMArena German | 1441 | 1266 |
| LMArena Japanese | 1422 | 1210 |
| LMArena Korean | 1412 | 1206 |
| LMArena Russian | 1436 | 1263 |
| LMArena Spanish | 1450 | 1283 |
Instruction Following Kimi K2.5 leads
Kimi K2.5: 75.5 (#60), Mistral Small 3.1: 63.8 (#225)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Instruction Following | 1431 | 1264 |
| IFEval | — | 75% |
Long Context Kimi K2.5 leads
Kimi K2.5: 52.1 (#7), Mistral Small 3.1: 39.5 (#172)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Longer Query | 1445 | 1300 |
| Fiction.LiveBench | 86.1% | — |
| CL-bench | 19.3% | — |
| CL-bench Life | 13.2% | — |
Writing & Preference Kimi K2.5 leads
Kimi K2.5: 65.3 (#51), Mistral Small 3.1: 37.2 (#254)
| Benchmark | Kimi K2.5 | Mistral Small 3.1 |
|---|---|---|
| LMArena Text | 1445 | 1278 |
| LMArena Creative Writing | 1423 | 1253 |
| EQ-Bench Creative Writing | 1579 | 761 |
| LMArena Multi-Turn | 1444 | 1270 |
| WildBench | — | 78.8% |
Frequently asked questions
Is Kimi K2.5 better than Mistral Small 3.1?
Kimi K2.5 is the stronger model overall, scoring 47.8 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 2.2× less per token, which makes it the better buy when Kimi K2.5's lead doesn't matter for your workload.
Which is cheaper, Kimi K2.5 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 K2.5 lists at $0.45 and $2.25.
Is Kimi K2.5 or Mistral Small 3.1 better for coding?
Kimi K2.5 scores higher on coding benchmarks: 48.7 versus 37.7 in the Noometry coding category.
Which has the bigger context window?
Kimi K2.5 does, with 262K tokens against 128K.
How many benchmarks do Kimi K2.5 and Mistral Small 3.1 share?
23 benchmarks have published results for both models. Kimi K2.5 has 51 scored results on Noometry and Mistral Small 3.1 has 28.