Model comparison

Kimi K3 vs Mistral Small 3.1

Kimi K3 is the stronger model overall, scoring 59.5 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 15× less per token, which makes it the better buy when Kimi K3's lead doesn't matter for your workload.

Last verified . 22 shared benchmarks.

Kimi K3 Moonshot AI

59.5

Rank #15 Confirmed

Mistral Small 3.1 Mistral AI

31.7

Rank #269 Confirmed

Summary

  • They share 22 benchmarks with published results for both. Kimi K3 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 K3 leads 74.2 to 14.7.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 97.2% for Kimi K3 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 $3 / $15 for Kimi K3.
  • Kimi K3 accepts more context: 1.05M tokens versus 128K.

Side by side

Kimi K3 and Mistral Small 3.1 specifications
Kimi K3Mistral Small 3.1
ProviderMoonshot AIMistral AI
Noometry Index59.531.7
Released2026-07-162025-03-17
WeightsOpenOpen
Context window1.05M128K
Max output1.05M102K
Input $ / M tokens$3$0.35
Output $ / M tokens$15$0.56
Results tracked5328

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Category by category

Coding Kimi K3 leads

Kimi K3: 61.0 (#10), Mistral Small 3.1: 38.3 (#179)

Coding benchmarks
BenchmarkKimi K3Mistral Small 3.1
LMArena Coding15081309
DeepSWE68.5%—
FrontierCode44.2%—
LMArena WebDev1654—
FrontierSWE25.9%—
SciCode59.5%—
WeirdML82.6%—
ALE-Bench1,524—

Agentic & Tool Use Not comparable

Kimi K3: 41.8 (#20), Mistral Small 3.1: —

Agentic & Tool Use benchmarks
BenchmarkKimi K3Mistral Small 3.1
APEX-Agents50.6%—
τ²-bench Banking37.1%—
PostTrainBench32%—
GBAEval48.3%—
GDP.pdf19%—
Vending-Bench 25,165—

Reasoning Kimi K3 leads

Kimi K3: 63.0 (#17), Mistral Small 3.1: 19.7 (#254)

Reasoning benchmarks
BenchmarkKimi K3Mistral Small 3.1
Chess Puzzles39%1%
LMArena Hard Prompts14961278
Epoch Capabilities Index157.45127.48
ARC-AGI-260.4%—
SimpleBench60.7%—
NYT Connections (extended)93.6%—
ARC-AGI-194.5%—
CritPt23.4%—
Mystery Game Puzzles26%—
DTBench91.2%—
LMCA52.7%—
Surface Evolver Bench95%—
ForecastBench61.1—

Math Kimi K3 leads

Kimi K3: 74.2 (#16), Mistral Small 3.1: 14.7 (#301)

Math benchmarks
BenchmarkKimi K3Mistral Small 3.1
OTIS Mock AIME 2024-202597.2%3.9%
LMArena Math14911262
FrontierMath (Tiers 1-3)72.2%—
FrontierMath Tier 439%—
MathArena Final-Answer Competitions87.8%—
ProofBench87%—
Omni-MATH—24.8%

Knowledge Kimi K3 leads

Kimi K3: 63.2 (#21), Mistral Small 3.1: 22.6 (#271)

Knowledge benchmarks
BenchmarkKimi K3Mistral Small 3.1
GPQA Diamond93.1%41.9%
LMArena Expert15211257
SimpleQA Verified50.6%—
MMLU-Pro—61%
GPQA (HELM)—39.2%

Multimodal Kimi K3 leads

Kimi K3: 37.8 (#70), Mistral Small 3.1: 33.2 (#99)

Multimodal benchmarks
BenchmarkKimi K3Mistral Small 3.1
LMArena Vision—1136
Blueprint-Bench 229.5%—
Furniture Assembly34.2%—

Multilingual Kimi K3 leads

Kimi K3: 56.3 (#21), Mistral Small 3.1: 41.2 (#209)

Multilingual benchmarks
BenchmarkKimi K3Mistral Small 3.1
LMArena Non-English14661255
LMArena Chinese15291253
LMArena French14911273
LMArena German14881266
LMArena Japanese14871208
LMArena Korean14581206
LMArena Russian14821263
LMArena Spanish14721283

Instruction Following Kimi K3 leads

Kimi K3: 77.7 (#14), Mistral Small 3.1: 63.6 (#230)

Instruction Following benchmarks
BenchmarkKimi K3Mistral Small 3.1
LMArena Instruction Following14831264
IFEval—75%

Long Context Kimi K3 leads

Kimi K3: 45.8 (#29), Mistral Small 3.1: 39.5 (#178)

Long Context benchmarks
BenchmarkKimi K3Mistral Small 3.1
LMArena Longer Query14941299

Writing & Preference Kimi K3 leads

Kimi K3: 76.6 (#4), Mistral Small 3.1: 37.0 (#259)

Writing & Preference benchmarks
BenchmarkKimi K3Mistral Small 3.1
LMArena Text14761277
LMArena Creative Writing14541253
EQ-Bench Creative Writing2082761
LMArena Multi-Turn14881270
WildBench—78.8%
EQ-Bench 41339—

Frequently asked questions

Is Kimi K3 better than Mistral Small 3.1?

Kimi K3 is the stronger model overall, scoring 59.5 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 15× less per token, which makes it the better buy when Kimi K3's lead doesn't matter for your workload.

Which is cheaper, Kimi K3 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 K3 lists at $3 and $15.

Is Kimi K3 or Mistral Small 3.1 better for coding?

Kimi K3 scores higher on coding benchmarks: 61.0 versus 38.3 in the Noometry coding category.

Which has the bigger context window?

Kimi K3 does, with 1.05M tokens against 128K.

How many benchmarks do Kimi K3 and Mistral Small 3.1 share?

22 benchmarks have published results for both models. Kimi K3 has 53 scored results on Noometry and Mistral Small 3.1 has 28.

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