Model comparison

GPT-5.1 vs Mistral Small 3

GPT-5.1 is the stronger model overall, scoring 48.8 to 30.9 on the Noometry Index. Mistral Small 3 costs 60× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 20 shared benchmarks.

GPT-5.1 OpenAI

48.8

Rank #47 Confirmed

Mistral Small 3 Mistral AI

30.9

Rank #268 Confirmed

Summary

  • They share 20 benchmarks with published results for both. GPT-5.1 scores higher in 8 categories and Mistral Small 3 in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.1 leads 50.3 to 15.3.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 88.6% for GPT-5.1 and 6.7% for Mistral Small 3.
  • Mistral Small 3 is cheaper at $0.05 / $0.08 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • GPT-5.1 accepts more context: 400K tokens versus 33K.
  • Mistral Small 3 has downloadable open weights; the other is API-only.

Side by side

GPT-5.1 and Mistral Small 3 specifications
GPT-5.1Mistral Small 3
ProviderOpenAIMistral AI
Noometry Index48.830.9
Released2025-11-132025-01-30
WeightsProprietaryOpen
Context window400K33K
Max output128K16K
Input $ / M tokens$1.25$0.05
Output $ / M tokens$10$0.08
Results tracked6324

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.9 (#59), Mistral Small 3: 36.0 (#203)

Coding benchmarks
BenchmarkGPT-5.1Mistral Small 3
LMArena Coding14541246
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
LMArena WebDev1395—
SciCode43.3%—
GSO13.7%—
WeirdML60.8%—
BigCodeBench Instruct—45.3%
LiveBench Coding72.5%—
BigCodeBench Complete—50.4%
ALE-Bench1,192—

Agentic & Tool Use Not comparable

GPT-5.1: 32.5 (#55), Mistral Small 3: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1Mistral Small 3
Terminal-Bench47.6%—
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning GPT-5.1 leads

GPT-5.1: 39.9 (#50), Mistral Small 3: 18.2 (#269)

Reasoning benchmarks
BenchmarkGPT-5.1Mistral Small 3
Chess Puzzles32%0%
LMArena Hard Prompts14571233
Epoch Capabilities Index149.66127.06
ARC-AGI-217.6%—
SimpleBench53.2%—
ARC-AGI-172.8%—
CritPt4.9%—
EnigmaEval11.2%—
LiveBench Reasoning95.8%—
Mystery Game Puzzles19%—
DTBench90.1%—
LiveBench Data Analysis72.1%—
LMCA43.9%—
ForecastBench58.1—
LiveBench78.8%—

Math GPT-5.1 leads

GPT-5.1: 50.3 (#45), Mistral Small 3: 15.3 (#290)

Math benchmarks
BenchmarkGPT-5.1Mistral Small 3
OTIS Mock AIME 2024-202588.6%6.7%
LMArena Math14461240
Omni-MATH46.4%—
LiveBench Math94.5%—
FrontierMath (Feb 2025 set)31%—
FrontierMath Tier 4 (v1)12.5%—

Knowledge GPT-5.1 leads

GPT-5.1: 50.5 (#65), Mistral Small 3: 25.0 (#258)

Knowledge benchmarks
BenchmarkGPT-5.1Mistral Small 3
GPQA Diamond87.6%47.3%
LMArena Expert14701202
Humanity's Last Exam23.7%—
SimpleQA Verified48%—
MMLU-Pro57.9%—
Confabulations—25.2%
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—

Multimodal Not comparable

GPT-5.1: 44.0 (#17), Mistral Small 3: —

Multimodal benchmarks
BenchmarkGPT-5.1Mistral Small 3
LMArena Vision1250—
VPCT58.7%—
LMArena Document1403—

Multilingual GPT-5.1 leads

GPT-5.1: 54.0 (#51), Mistral Small 3: 37.5 (#231)

Multilingual benchmarks
BenchmarkGPT-5.1Mistral Small 3
LMArena Non-English14311198
LMArena Chinese14951204
LMArena French14511202
LMArena German14391211
LMArena Japanese14531111
LMArena Korean14011188
LMArena Russian14351216
LMArena Spanish1430—

Instruction Following GPT-5.1 leads

GPT-5.1: 84.0 (#1), Mistral Small 3: 63.9 (#224)

Instruction Following benchmarks
BenchmarkGPT-5.1Mistral Small 3
LMArena Instruction Following14421214
LiveBench Instruction Following93.3%—
IFEval93.5%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), Mistral Small 3: 37.8 (#206)

Long Context benchmarks
BenchmarkGPT-5.1Mistral Small 3
LMArena Longer Query14481246
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.7 (#53), Mistral Small 3: 32.4 (#275)

Writing & Preference benchmarks
BenchmarkGPT-5.1Mistral Small 3
LMArena Text14431234
LMArena Creative Writing14271195
LMArena Multi-Turn14491217
EQ-Bench Creative Writing—707
WildBench86.3%—
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than Mistral Small 3?

GPT-5.1 is the stronger model overall, scoring 48.8 to 30.9 on the Noometry Index. Mistral Small 3 costs 60× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Which is cheaper, GPT-5.1 or Mistral Small 3?

Mistral Small 3 is cheaper. It lists at $0.05 per million input tokens and $0.08 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is GPT-5.1 or Mistral Small 3 better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.9 versus 36.0 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1 does, with 400K tokens against 33K.

How many benchmarks do GPT-5.1 and Mistral Small 3 share?

20 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Mistral Small 3 has 24.

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