Model comparison

GPT-5.2 Codex vs Mistral Small 3.1

GPT-5.2 Codex is the stronger model overall, scoring 42.2 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 12× less per token, which makes it the better buy when GPT-5.2 Codex's lead doesn't matter for your workload.

Last verified . 0 shared benchmarks.

GPT-5.2 Codex OpenAI

42.2

Rank #107 Reported

Mistral Small 3.1 Mistral AI

31.4

Rank #263 Confirmed

Summary

  • The widest gap is in coding, where GPT-5.2 Codex leads 45.4 to 37.7.
  • Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $1.75 / $14 for GPT-5.2 Codex.
  • GPT-5.2 Codex accepts more context: 400K tokens versus 128K.
  • Mistral Small 3.1 has downloadable open weights; the other is API-only.

Side by side

GPT-5.2 Codex and Mistral Small 3.1 specifications
GPT-5.2 CodexMistral Small 3.1
ProviderOpenAIMistral AI
Noometry Index42.231.4
Released2025-12-182025-03-17
WeightsProprietaryOpen
Context window400K128K
Max output128K102K
Input $ / M tokens$1.75$0.35
Output $ / M tokens$14$0.56
Results tracked528

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Category by category

Coding GPT-5.2 Codex leads

GPT-5.2 Codex: 45.4 (#66), Mistral Small 3.1: 37.7 (#175)

Coding benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
SWE-bench Verified (bash only)72.8%—
LMArena WebDev1339—
SWE-bench Multilingual66.3%—
LMArena Coding—1309
ALE-Bench1,300—

Agentic & Tool Use Not comparable

GPT-5.2 Codex: 40.7 (#20), Mistral Small 3.1: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
Terminal-Bench66.5%—

Reasoning Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 18.9 (#249)

Reasoning benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
Chess Puzzles—1%
LMArena Hard Prompts—1278
Epoch Capabilities Index—127.48

Math Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 13.7 (#295)

Math benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
OTIS Mock AIME 2024-2025—3.9%
Omni-MATH—24.8%
LMArena Math—1261

Knowledge Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 22.6 (#266)

Knowledge benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
GPQA Diamond—41.9%
MMLU-Pro—61%
GPQA (HELM)—39.2%
LMArena Expert—1258

Multimodal Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 32.6 (#93)

Multimodal benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
LMArena Vision—1136

Multilingual Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 41.4 (#204)

Multilingual benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
LMArena Non-English—1255
LMArena Chinese—1254
LMArena French—1270
LMArena German—1266
LMArena Japanese—1210
LMArena Korean—1206
LMArena Russian—1263
LMArena Spanish—1283

Instruction Following Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 63.8 (#225)

Instruction Following benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
IFEval—75%
LMArena Instruction Following—1264

Long Context Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 39.5 (#172)

Long Context benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
LMArena Longer Query—1300

Writing & Preference Not comparable

GPT-5.2 Codex: —, Mistral Small 3.1: 37.2 (#254)

Writing & Preference benchmarks
BenchmarkGPT-5.2 CodexMistral Small 3.1
LMArena Text—1278
LMArena Creative Writing—1253
EQ-Bench Creative Writing—761
WildBench—78.8%
LMArena Multi-Turn—1270

Frequently asked questions

Is GPT-5.2 Codex better than Mistral Small 3.1?

GPT-5.2 Codex is the stronger model overall, scoring 42.2 to 31.4 on the Noometry Index. Mistral Small 3.1 costs 12× less per token, which makes it the better buy when GPT-5.2 Codex's lead doesn't matter for your workload.

Which is cheaper, GPT-5.2 Codex or Mistral Small 3.1?

Mistral Small 3.1 is cheaper. It lists at $0.35 per million input tokens and $0.56 per million output tokens; GPT-5.2 Codex lists at $1.75 and $14.

Is GPT-5.2 Codex or Mistral Small 3.1 better for coding?

GPT-5.2 Codex scores higher on coding benchmarks: 45.4 versus 37.7 in the Noometry coding category.

Which has the bigger context window?

GPT-5.2 Codex does, with 400K tokens against 128K.

How many benchmarks do GPT-5.2 Codex and Mistral Small 3.1 share?

0 benchmarks have published results for both models. GPT-5.2 Codex has 5 scored results on Noometry and Mistral Small 3.1 has 28.

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