Noometry

Model comparison

GPT-5.3 Chat vs Mistral Small 3.1

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 12× less per token, which makes it the better buy when GPT-5.3 Chat's lead doesn't matter for your workload.

Last verified . 18 shared benchmarks.

GPT-5.3 Chat OpenAI

42.8

Rank #109 Confirmed

Mistral Small 3.1 Mistral AI

31.7

Rank #269 Confirmed

Summary

  • They share 18 benchmarks with published results for both. GPT-5.3 Chat scores higher in 8 categories and Mistral Small 3.1 in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where GPT-5.3 Chat leads 63.1 to 37.0.
  • Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
  • Mistral Small 3.1 has downloadable open weights; the other is API-only.

Side by side

GPT-5.3 ChatMistral Small 3.1
ProviderOpenAIMistral AI
Noometry Index42.831.7
Released2026-03-032025-03-17
WeightsProprietaryOpen
Context window128K128K
Max output16K102K
Input $ / M tokens$1.75$0.35
Output $ / M tokens$14$0.56
Results tracked1828

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Category by category

Coding GPT-5.3 Chat leads

GPT-5.3 Chat: 41.4 (#124), Mistral Small 3.1: 38.3 (#179)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Coding14081309

Reasoning GPT-5.3 Chat leads

GPT-5.3 Chat: 28.5 (#102), Mistral Small 3.1: 19.7 (#254)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Hard Prompts13991278
Chess Puzzles—1%
Epoch Capabilities Index—127.48

Math GPT-5.3 Chat leads

GPT-5.3 Chat: 38.2 (#142), Mistral Small 3.1: 14.7 (#301)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Math13891262
OTIS Mock AIME 2024-2025—3.9%
Omni-MATH—24.8%

Knowledge GPT-5.3 Chat leads

GPT-5.3 Chat: 38.8 (#140), Mistral Small 3.1: 22.6 (#271)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Expert13971257
GPQA Diamond—41.9%
MMLU-Pro—61%
GPQA (HELM)—39.2%

Multimodal Not comparable

GPT-5.3 Chat: —, Mistral Small 3.1: 33.2 (#99)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Vision—1136

Multilingual GPT-5.3 Chat leads

GPT-5.3 Chat: 50.3 (#124), Mistral Small 3.1: 41.2 (#209)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Non-English13821255
LMArena Chinese14321253
LMArena French13971273
LMArena German13841266
LMArena Japanese13521208
LMArena Korean13461206
LMArena Russian14001263
LMArena Spanish13711283

Instruction Following GPT-5.3 Chat leads

GPT-5.3 Chat: 72.8 (#129), Mistral Small 3.1: 63.6 (#230)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Instruction Following13781264
IFEval—75%

Long Context GPT-5.3 Chat leads

GPT-5.3 Chat: 42.6 (#120), Mistral Small 3.1: 39.5 (#178)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Longer Query13961299

Writing & Preference GPT-5.3 Chat leads

GPT-5.3 Chat: 63.1 (#68), Mistral Small 3.1: 37.0 (#259)

BenchmarkGPT-5.3 ChatMistral Small 3.1
LMArena Text13891277
LMArena Creative Writing13551253
EQ-Bench Creative Writing1690761
LMArena Multi-Turn14121270
WildBench—78.8%

Frequently asked questions

Is GPT-5.3 Chat better than Mistral Small 3.1?

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 12× less per token, which makes it the better buy when GPT-5.3 Chat's lead doesn't matter for your workload.

Which is cheaper, GPT-5.3 Chat 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-5.3 Chat lists at $1.75 and $14.

Is GPT-5.3 Chat or Mistral Small 3.1 better for coding?

GPT-5.3 Chat scores higher on coding benchmarks: 41.4 versus 38.3 in the Noometry coding category.

Which has the bigger context window?

Both accept 128K tokens.

How many benchmarks do GPT-5.3 Chat and Mistral Small 3.1 share?

18 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Mistral Small 3.1 has 28.

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