Model comparison

GPT-5.1-Codex vs Mistral Nemo

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 25.9 on the Noometry Index. Mistral Nemo costs 23× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.

Last verified . 0 shared benchmarks.

GPT-5.1-Codex OpenAI

38.2

Rank #178 Reported

Mistral Nemo Mistral AI

25.9

Rank #332 Confirmed

Summary

  • The widest gap is in agentic & tool use, where GPT-5.1-Codex leads 37.8 to 23.3.
  • Mistral Nemo is cheaper at $0.15 / $0.15 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
  • GPT-5.1-Codex accepts more context: 400K tokens versus 128K.
  • Mistral Nemo has downloadable open weights; the other is API-only.

Side by side

GPT-5.1-Codex and Mistral Nemo specifications
GPT-5.1-CodexMistral Nemo
ProviderOpenAIMistral AI
Noometry Index38.225.9
Released2025-11-122024-07-01
WeightsProprietaryOpen
Context window400K128K
Max output128K128K
Input $ / M tokens$1.25$0.15
Output $ / M tokens$10$0.15
Results tracked610

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Category by category

Coding Not comparable

GPT-5.1-Codex: 41.7 (#107), Mistral Nemo: —

Coding benchmarks
BenchmarkGPT-5.1-CodexMistral Nemo
SWE-bench Verified (bash only)66%—
LMArena WebDev1337—
ALE-Bench1,245—

Agentic & Tool Use GPT-5.1-Codex leads

GPT-5.1-Codex: 37.8 (#32), Mistral Nemo: 23.3 (#118)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1-CodexMistral Nemo
Terminal-Bench60.4%—
Berkeley Function Calling Leaderboard—27.6%
BALROG—17.6%
METR Time Horizons70.8%—

Reasoning Not comparable

GPT-5.1-Codex: —, Mistral Nemo: 19.9 (#230)

Reasoning benchmarks
BenchmarkGPT-5.1-CodexMistral Nemo
DTBench—48.6%
Epoch Capabilities Index—118.63
PIQA—83.5%

Math GPT-5.1-Codex leads

GPT-5.1-Codex: 29.3 (#218), Mistral Nemo: 23.5 (#263)

Math benchmarks
BenchmarkGPT-5.1-CodexMistral Nemo
ProofBench9%—
MATH Level 5—10.8%
GSM8K—84.2%

Knowledge Not comparable

GPT-5.1-Codex: —, Mistral Nemo: 12.3 (#293)

Knowledge benchmarks
BenchmarkGPT-5.1-CodexMistral Nemo
GPQA Diamond—29.9%
BoolQ—82.5%

Writing & Preference Not comparable

GPT-5.1-Codex: —, Mistral Nemo: 28.6 (#291)

Writing & Preference benchmarks
BenchmarkGPT-5.1-CodexMistral Nemo
EQ-Bench Creative Writing—881

Frequently asked questions

Is GPT-5.1-Codex better than Mistral Nemo?

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 25.9 on the Noometry Index. Mistral Nemo costs 23× less per token, which makes it the better buy when GPT-5.1-Codex's lead doesn't matter for your workload.

Which is cheaper, GPT-5.1-Codex or Mistral Nemo?

Mistral Nemo is cheaper. It lists at $0.15 per million input tokens and $0.15 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 128K.

How many benchmarks do GPT-5.1-Codex and Mistral Nemo share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Mistral Nemo has 10.

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