Model comparison

Mistral Small 3.1 vs o3-mini

o3-mini is the stronger model overall, scoring 36.7 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 4.8× less per token, which makes it the better buy when o3-mini's lead doesn't matter for your workload.

Last verified . 21 shared benchmarks.

Mistral Small 3.1 Mistral AI

31.7

Rank #269 Confirmed

o3-mini OpenAI

36.7

Rank #212 Confirmed

Summary

  • They share 21 benchmarks with published results for both. Mistral Small 3.1 scores higher in 2 categories and o3-mini in 6 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where o3-mini leads 38.3 to 22.6.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 3.9% for Mistral Small 3.1 and 76.9% for o3-mini.
  • Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $1.10 / $4.40 for o3-mini.
  • o3-mini accepts more context: 200K tokens versus 128K.
  • Mistral Small 3.1 has downloadable open weights; the other is API-only.

Side by side

Mistral Small 3.1 and o3-mini specifications
Mistral Small 3.1o3-mini
ProviderMistral AIOpenAI
Noometry Index31.736.7
Released2025-03-172024-12-20
WeightsOpenProprietary
Context window128K200K
Max output102K100K
Input $ / M tokens$0.35$1.10
Output $ / M tokens$0.56$4.40
Results tracked2851

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding o3-mini leads

Mistral Small 3.1: 38.3 (#179), o3-mini: 40.8 (#132)

Coding benchmarks
BenchmarkMistral Small 3.1o3-mini
LMArena Coding13091378
Aider Polyglot—60.4%
SciCode—39.8%
GSO—1.3%
WeirdML—43.7%
LiveBench Coding—82.7%
CadEval—54%

Agentic & Tool Use Not comparable

Mistral Small 3.1: —, o3-mini: 29.6 (#84)

Agentic & Tool Use benchmarks
BenchmarkMistral Small 3.1o3-mini
Cybench—22.5%

Reasoning Mistral Small 3.1 leads

Mistral Small 3.1: 19.7 (#254), o3-mini: 16.3 (#305)

Reasoning benchmarks
BenchmarkMistral Small 3.1o3-mini
Chess Puzzles1%17%
LMArena Hard Prompts12781366
Epoch Capabilities Index127.48140.34
ARC-AGI-2—3%
SimpleBench—22.8%
ARC-AGI-1—34.5%
CritPt—0.3%
LiveBench Reasoning—89.6%
Mystery Game Puzzles—7%
DTBench—68.8%
LiveBench Data Analysis—70.6%
LMCA—19%
ForecastBench—59.6
LiveBench—75.9%

Math o3-mini leads

Mistral Small 3.1: 14.7 (#301), o3-mini: 28.1 (#244)

Math benchmarks
BenchmarkMistral Small 3.1o3-mini
OTIS Mock AIME 2024-20253.9%76.9%
LMArena Math12621396
FrontierMath (Tiers 1-3)—18.6%
FrontierMath Tier 4—0%
Omni-MATH24.8%—
LiveBench Math—77.3%
MATH Level 5—96.5%
FrontierMath (Feb 2025 set)—12.4%
FrontierMath Tier 4 (v1)—4.2%

Knowledge o3-mini leads

Mistral Small 3.1: 22.6 (#271), o3-mini: 38.3 (#146)

Knowledge benchmarks
BenchmarkMistral Small 3.1o3-mini
GPQA Diamond41.9%77%
LMArena Expert12571364
SimpleQA Verified—15.3%
MMLU-Pro61%—
Confabulations—17.9%
GPQA (HELM)39.2%—

Multimodal Not comparable

Mistral Small 3.1: 33.2 (#99), o3-mini: —

Multimodal benchmarks
BenchmarkMistral Small 3.1o3-mini
LMArena Vision1136—

Multilingual o3-mini leads

Mistral Small 3.1: 41.2 (#209), o3-mini: 45.7 (#164)

Multilingual benchmarks
BenchmarkMistral Small 3.1o3-mini
LMArena Non-English12551319
LMArena Chinese12531379
LMArena French12731334
LMArena German12661303
LMArena Japanese12081286
LMArena Korean12061314
LMArena Russian12631304
LMArena Spanish12831321

Instruction Following o3-mini leads

Mistral Small 3.1: 63.6 (#230), o3-mini: 75.1 (#72)

Instruction Following benchmarks
BenchmarkMistral Small 3.1o3-mini
LMArena Instruction Following12641337
LiveBench Instruction Following—84.4%
IFEval75%—

Long Context Mistral Small 3.1 leads

Mistral Small 3.1: 39.5 (#178), o3-mini: 33.8 (#256)

Long Context benchmarks
BenchmarkMistral Small 3.1o3-mini
LMArena Longer Query12991343
Fiction.LiveBench—50%

Writing & Preference o3-mini leads

Mistral Small 3.1: 37.0 (#259), o3-mini: 50.3 (#182)

Writing & Preference benchmarks
BenchmarkMistral Small 3.1o3-mini
LMArena Text12771337
LMArena Creative Writing12531286
LMArena Multi-Turn12701320
Short-Story Creative Writing—61.7%
EQ-Bench Creative Writing761—
WildBench78.8%—
LiveBench Language—50.7%

Frequently asked questions

Is Mistral Small 3.1 better than o3-mini?

o3-mini is the stronger model overall, scoring 36.7 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 4.8× less per token, which makes it the better buy when o3-mini's lead doesn't matter for your workload.

Which is cheaper, Mistral Small 3.1 or o3-mini?

Mistral Small 3.1 is cheaper. It lists at $0.35 per million input tokens and $0.56 per million output tokens; o3-mini lists at $1.10 and $4.40.

Is Mistral Small 3.1 or o3-mini better for coding?

o3-mini scores higher on coding benchmarks: 40.8 versus 38.3 in the Noometry coding category.

Which has the bigger context window?

o3-mini does, with 200K tokens against 128K.

How many benchmarks do Mistral Small 3.1 and o3-mini share?

21 benchmarks have published results for both models. Mistral Small 3.1 has 28 scored results on Noometry and o3-mini has 51.

Related comparisons

Go deeper