Model comparison

gpt-oss-20b vs Mistral Large 3

Mistral Large 3 is the stronger model overall, scoring 38.6 to 32.1 on the Noometry Index. gpt-oss-20b costs 10× less per token, which makes it the better buy when Mistral Large 3's lead doesn't matter for your workload.

Last verified . 18 shared benchmarks.

gpt-oss-20b OpenAI

32.1

Rank #249 Confirmed

Mistral Large 3 Mistral AI

38.6

Rank #172 Confirmed

Summary

  • They share 18 benchmarks with published results for both. gpt-oss-20b scores higher in 3 categories and Mistral Large 3 in 5 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Mistral Large 3 leads 60.2 to 35.8.
  • gpt-oss-20b is cheaper at $0.018 / $0.09 per million input/output tokens, against $0.25 / $0.75 for Mistral Large 3.
  • Mistral Large 3 accepts more context: 262K tokens versus 131K.

Side by side

gpt-oss-20b and Mistral Large 3 specifications
gpt-oss-20bMistral Large 3
ProviderOpenAIMistral AI
Noometry Index32.138.6
Released2025-08-052025-12-02
WeightsOpenOpen
Context window131K262K
Max output16K8K
Input $ / M tokens$0.018$0.25
Output $ / M tokens$0.09$0.75
Results tracked3424

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Category by category

Coding gpt-oss-20b leads

gpt-oss-20b: 37.1 (#185), Mistral Large 3: 34.1 (#230)

Coding benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Coding13071447
LMArena WebDev—1230
SciCode34.4%—
WeirdML40.9%—
ALE-Bench566.05—

Agentic & Tool Use Not comparable

gpt-oss-20b: 9.2 (#146), Mistral Large 3: —

Agentic & Tool Use benchmarks
Benchmarkgpt-oss-20bMistral Large 3
Terminal-Bench3.4%—

Reasoning gpt-oss-20b leads

gpt-oss-20b: 18.8 (#251), Mistral Large 3: 14.6 (#314)

Reasoning benchmarks
Benchmarkgpt-oss-20bMistral Large 3
Kagi LLM Benchmark53.2%50.9%
LMArena Hard Prompts12741429
NYT Connections (extended)—7.5%
CritPt1.4%—
Chess Puzzles4%—
Thematic Generalization—23%
DTBench68%—
LMCA14.5%—
Epoch Capabilities Index137.81—

Math gpt-oss-20b leads

gpt-oss-20b: 37.6 (#93), Mistral Large 3: 36.0 (#131)

Math benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Math13171415
OTIS Mock AIME 2024-202565.3%—
Omni-MATH56.5%—

Knowledge Too close to call

gpt-oss-20b: 34.6 (#186), Mistral Large 3: 35.5 (#173)

Knowledge benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Expert12581421
GPQA Diamond60.8%—
MMLU-Pro74%—
Vectara Hallucination Rate—14.5%
GPQA (HELM)59.4%—

Multimodal Not comparable

gpt-oss-20b: —, Mistral Large 3: 37.6 (#65)

Multimodal benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Vision—1222

Multilingual Mistral Large 3 leads

gpt-oss-20b: 42.4 (#192), Mistral Large 3: 52.6 (#79)

Multilingual benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Non-English12691412
LMArena Chinese13111448
LMArena German12491438
LMArena Japanese12451399
LMArena Korean12391384
LMArena Russian12791412
LMArena Spanish12671437
LMArena French—1456

Instruction Following Mistral Large 3 leads

gpt-oss-20b: 62.0 (#235), Mistral Large 3: 74.1 (#104)

Instruction Following benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Instruction Following12361402
IFEval73.2%—

Long Context Mistral Large 3 leads

gpt-oss-20b: 37.9 (#203), Mistral Large 3: 43.1 (#102)

Long Context benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Longer Query12511413

Writing & Preference Mistral Large 3 leads

gpt-oss-20b: 35.8 (#260), Mistral Large 3: 60.2 (#100)

Writing & Preference benchmarks
Benchmarkgpt-oss-20bMistral Large 3
LMArena Text12881427
LMArena Creative Writing12011385
EQ-Bench Creative Writing6661412
LMArena Multi-Turn12681429
WildBench73.7%—

Frequently asked questions

Is gpt-oss-20b better than Mistral Large 3?

Mistral Large 3 is the stronger model overall, scoring 38.6 to 32.1 on the Noometry Index. gpt-oss-20b costs 10× less per token, which makes it the better buy when Mistral Large 3's lead doesn't matter for your workload.

Which is cheaper, gpt-oss-20b or Mistral Large 3?

gpt-oss-20b is cheaper. It lists at $0.018 per million input tokens and $0.09 per million output tokens; Mistral Large 3 lists at $0.25 and $0.75.

Is gpt-oss-20b or Mistral Large 3 better for coding?

gpt-oss-20b scores higher on coding benchmarks: 37.1 versus 34.1 in the Noometry coding category.

Which has the bigger context window?

Mistral Large 3 does, with 262K tokens against 131K.

How many benchmarks do gpt-oss-20b and Mistral Large 3 share?

18 benchmarks have published results for both models. gpt-oss-20b has 34 scored results on Noometry and Mistral Large 3 has 24.

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