Model comparison

Mistral Small 3 vs o3

o3 is the stronger model overall, scoring 47.5 to 31.2 on the Noometry Index. Mistral Small 3 costs 61× less per token, which makes it the better buy when o3's lead doesn't matter for your workload.

Last verified . 22 shared benchmarks.

Mistral Small 3 Mistral AI

31.2

Rank #278 Confirmed

o3 OpenAI

47.5

Rank #61 Confirmed

Summary

  • They share 22 benchmarks with published results for both. Mistral Small 3 scores higher in 0 categories and o3 in 8 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where o3 leads 50.2 to 16.3.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 6.7% for Mistral Small 3 and 84.4% for o3.
  • Mistral Small 3 is cheaper at $0.05 / $0.08 per million input/output tokens, against $2 / $8 for o3.
  • o3 accepts more context: 200K tokens versus 33K.
  • Mistral Small 3 has downloadable open weights; the other is API-only.

Side by side

Mistral Small 3 and o3 specifications
Mistral Small 3o3
ProviderMistral AIOpenAI
Noometry Index31.247.5
Released2025-01-302025-04-16
WeightsOpenProprietary
Context window33K200K
Max output16K100K
Input $ / M tokens$0.05$2
Output $ / M tokens$0.08$8
Results tracked2463

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Category by category

Coding o3 leads

Mistral Small 3: 36.5 (#207), o3: 46.8 (#64)

Coding benchmarks
BenchmarkMistral Small 3o3
LMArena Coding12461408
SWE-bench Verified—62.3%
SWE-bench Verified (bash only)—58.4%
Aider Polyglot—81.3%
GSO—8.8%
WeirdML—52.4%
BigCodeBench Instruct45.3%—
BigCodeBench Complete50.4%—
CadEval—74%
ALE-Bench—933.55

Agentic & Tool Use Not comparable

Mistral Small 3: —, o3: 34.5 (#44)

Agentic & Tool Use benchmarks
BenchmarkMistral Small 3o3
Berkeley Function Calling Leaderboard—63%
GDPval—30.8%
DeepResearch Bench—45.2%
OSWorld—23%
LMArena Search—1144
METR Time Horizons—65.4%

Reasoning o3 leads

Mistral Small 3: 18.9 (#273), o3: 32.0 (#78)

Reasoning benchmarks
BenchmarkMistral Small 3o3
Chess Puzzles0%38%
LMArena Hard Prompts12331402
Epoch Capabilities Index127.07146.86
ARC-AGI-2—6.5%
SimpleBench—53.1%
Kagi LLM Benchmark—67.6%
ARC-AGI-1—60.8%
CritPt—1.4%
EnigmaEval—13.1%
Mystery Game Puzzles—29%
DTBench—84.8%
LMCA—39.7%
ForecastBench—62.5

Math o3 leads

Mistral Small 3: 16.3 (#295), o3: 50.2 (#58)

Math benchmarks
BenchmarkMistral Small 3o3
OTIS Mock AIME 2024-20256.7%84.4%
LMArena Math12401426
FrontierMath (Tiers 1-3)—33.3%
Omni-MATH—71.4%
MATH Level 5—97.8%
FrontierMath (Feb 2025 set)—18.7%
FrontierMath Tier 4 (v1)—2.1%

Knowledge o3 leads

Mistral Small 3: 25.1 (#263), o3: 54.6 (#52)

Knowledge benchmarks
BenchmarkMistral Small 3o3
GPQA Diamond47.3%81.8%
Confabulations25.2%14.4%
LMArena Expert12021402
Humanity's Last Exam—20.3%
SimpleQA Verified—49.4%
MMLU-Pro—85.9%
GPQA (HELM)—75.3%

Multimodal Not comparable

Mistral Small 3: —, o3: 41.4 (#36)

Multimodal benchmarks
BenchmarkMistral Small 3o3
LMArena Vision—1214
GeoBench—74%
VPCT—52%

Multilingual o3 leads

Mistral Small 3: 37.3 (#236), o3: 51.7 (#105)

Multilingual benchmarks
BenchmarkMistral Small 3o3
LMArena Non-English11981401
LMArena Chinese12041437
LMArena French12031430
LMArena German12111420
LMArena Japanese11111403
LMArena Korean11881370
LMArena Russian12161406
LMArena Spanish—1395

Instruction Following o3 leads

Mistral Small 3: 63.7 (#229), o3: 72.8 (#127)

Instruction Following benchmarks
BenchmarkMistral Small 3o3
LMArena Instruction Following12141368
IFEval—86.9%

Long Context o3 leads

Mistral Small 3: 37.8 (#211), o3: 53.3 (#6)

Long Context benchmarks
BenchmarkMistral Small 3o3
LMArena Longer Query12461372
Fiction.LiveBench—88.9%
CL-bench—17.8%

Writing & Preference o3 leads

Mistral Small 3: 32.2 (#280), o3: 63.5 (#64)

Writing & Preference benchmarks
BenchmarkMistral Small 3o3
LMArena Text12341410
LMArena Creative Writing11951359
EQ-Bench Creative Writing7071676
LMArena Multi-Turn12171405
Short-Story Creative Writing—83.9%
WildBench—86.1%

Frequently asked questions

Is Mistral Small 3 better than o3?

o3 is the stronger model overall, scoring 47.5 to 31.2 on the Noometry Index. Mistral Small 3 costs 61× less per token, which makes it the better buy when o3's lead doesn't matter for your workload.

Which is cheaper, Mistral Small 3 or o3?

Mistral Small 3 is cheaper. It lists at $0.05 per million input tokens and $0.08 per million output tokens; o3 lists at $2 and $8.

Is Mistral Small 3 or o3 better for coding?

o3 scores higher on coding benchmarks: 46.8 versus 36.5 in the Noometry coding category.

Which has the bigger context window?

o3 does, with 200K tokens against 33K.

How many benchmarks do Mistral Small 3 and o3 share?

22 benchmarks have published results for both models. Mistral Small 3 has 24 scored results on Noometry and o3 has 63.

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