Model comparison

gpt-oss-120b vs Mistral Small

gpt-oss-120b is the stronger model overall, scoring 36.3 to 33.4 on the Noometry Index.

Last verified . 26 shared benchmarks.

gpt-oss-120b OpenAI

36.3

Rank #217 Confirmed

Mistral Small Mistral AI

33.4

Rank #243 Confirmed

Summary

  • They share 26 benchmarks with published results for both. gpt-oss-120b scores higher in 5 categories and Mistral Small in 4 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in math, where gpt-oss-120b leads 52.5 to 16.4.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 88.9% for gpt-oss-120b and 5.8% for Mistral Small.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $0.15 / $0.60 for Mistral Small.
  • Mistral Small accepts more context: 262K tokens versus 131K.

Side by side

gpt-oss-120b and Mistral Small specifications
gpt-oss-120bMistral Small
ProviderOpenAIMistral AI
Noometry Index36.333.4
Released2025-08-052024-02-26
WeightsOpenOpen
Context window131K262K
Max output41K256K
Input $ / M tokens$0.037$0.15
Output $ / M tokens$0.17$0.60
Results tracked4839

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Category by category

Coding Too close to call

gpt-oss-120b: 33.5 (#256), Mistral Small: 34.0 (#247)

Coding benchmarks
Benchmarkgpt-oss-120bMistral Small
SciCode36%26.5%
LMArena Coding13801362
ALE-Bench575.62497.62
SWE-bench Verified (bash only)26%—
Aider Polyglot41.8%—
WeirdML48.2%—
BigCodeBench Instruct—36.1%
LiveBench Coding—36.2%
BigCodeBench Complete—46.6%
AlgoTune1.41—

Agentic & Tool Use Mistral Small leads

gpt-oss-120b: 12.2 (#153), Mistral Small: 28.1 (#93)

Agentic & Tool Use benchmarks
Benchmarkgpt-oss-120bMistral Small
Terminal-Bench18.7%—
APEX-Agents4.4%—
Berkeley Function Calling Leaderboard—37.1%
METR Time Horizons56.6%—
Vending-Bench 2-21.53—

Reasoning Too close to call

gpt-oss-120b: 20.0 (#245), Mistral Small: 19.8 (#250)

Reasoning benchmarks
Benchmarkgpt-oss-120bMistral Small
Kagi LLM Benchmark58.6%37.8%
CritPt1.1%0%
LMArena Hard Prompts13641335
DTBench76.3%70.9%
LMCA22.1%20.6%
SimpleBench22.1%—
Chess Puzzles20%—
LiveBench Reasoning—44.8%
Mystery Game Puzzles2%—
LiveBench Data Analysis—53.7%
Surface Evolver Bench25%—
Epoch Capabilities Index139.93—
LiveBench—44%

Math gpt-oss-120b leads

gpt-oss-120b: 52.5 (#50), Mistral Small: 16.4 (#293)

Math benchmarks
Benchmarkgpt-oss-120bMistral Small
OTIS Mock AIME 2024-202588.9%5.8%
LMArena Math13891341
Omni-MATH68.8%—
LiveBench Math—39.9%
MATH Level 5—46.8%

Knowledge gpt-oss-120b leads

gpt-oss-120b: 42.4 (#96), Mistral Small: 31.0 (#222)

Knowledge benchmarks
Benchmarkgpt-oss-120bMistral Small
GPQA Diamond75.8%47.5%
Vectara Hallucination Rate14.2%5.1%
LMArena Expert13561291
MMLU-Pro79.5%—
Confabulations15.7%—
GPQA (HELM)68.4%—
MMLU—68.7%

Multimodal Not comparable

gpt-oss-120b: —, Mistral Small: 33.5 (#96)

Multimodal benchmarks
Benchmarkgpt-oss-120bMistral Small
LMArena Vision—1142

Multilingual gpt-oss-120b leads

gpt-oss-120b: 48.0 (#147), Mistral Small: 45.5 (#169)

Multilingual benchmarks
Benchmarkgpt-oss-120bMistral Small
LMArena Non-English13511315
LMArena Chinese13851340
LMArena French13691337
LMArena German13531340
LMArena Japanese13311275
LMArena Korean12821259
LMArena Russian13431324
LMArena Spanish13891346

Instruction Following gpt-oss-120b leads

gpt-oss-120b: 69.3 (#173), Mistral Small: 66.4 (#209)

Instruction Following benchmarks
Benchmarkgpt-oss-120bMistral Small
LMArena Instruction Following13181310
LiveBench Instruction Following—63.7%
IFEval83.6%—

Long Context Mistral Small leads

gpt-oss-120b: 31.4 (#278), Mistral Small: 40.4 (#156)

Long Context benchmarks
Benchmarkgpt-oss-120bMistral Small
LMArena Longer Query13191327
Fiction.LiveBench44.4%—

Writing & Preference Mistral Small leads

gpt-oss-120b: 46.5 (#217), Mistral Small: 52.5 (#171)

Writing & Preference benchmarks
Benchmarkgpt-oss-120bMistral Small
LMArena Text13651338
LMArena Creative Writing12751305
LMArena Multi-Turn13401344
Short-Story Creative Writing77.1%—
EQ-Bench Creative Writing961—
WildBench84.5%—
LiveBench Language—30.5%

Frequently asked questions

Is gpt-oss-120b better than Mistral Small?

gpt-oss-120b is the stronger model overall, scoring 36.3 to 33.4 on the Noometry Index.

Which is cheaper, gpt-oss-120b or Mistral Small?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; Mistral Small lists at $0.15 and $0.60.

Is gpt-oss-120b or Mistral Small better for coding?

They score almost the same on coding (33.5 vs 34.0); test both on your own repository before choosing.

Which has the bigger context window?

Mistral Small does, with 262K tokens against 131K.

How many benchmarks do gpt-oss-120b and Mistral Small share?

26 benchmarks have published results for both models. gpt-oss-120b has 48 scored results on Noometry and Mistral Small has 39.

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