Model comparison

GPT-5.3 Chat vs Mistral Small

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 33.4 on the Noometry Index. Mistral Small costs 18× less per token, which makes it the better buy when GPT-5.3 Chat's lead doesn't matter for your workload.

Last verified . 17 shared benchmarks.

GPT-5.3 Chat OpenAI

42.8

Rank #109 Confirmed

Mistral Small Mistral AI

33.4

Rank #243 Confirmed

Summary

  • They share 17 benchmarks with published results for both. GPT-5.3 Chat scores higher in 8 categories and Mistral Small in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.3 Chat leads 38.2 to 16.4.
  • Mistral Small is cheaper at $0.15 / $0.60 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
  • Mistral Small accepts more context: 262K tokens versus 128K.
  • Mistral Small has downloadable open weights; the other is API-only.

Side by side

GPT-5.3 Chat and Mistral Small specifications
GPT-5.3 ChatMistral Small
ProviderOpenAIMistral AI
Noometry Index42.833.4
Released2026-03-032024-02-26
WeightsProprietaryOpen
Context window128K262K
Max output16K256K
Input $ / M tokens$1.75$0.15
Output $ / M tokens$14$0.60
Results tracked1839

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Category by category

Coding GPT-5.3 Chat leads

GPT-5.3 Chat: 41.4 (#124), Mistral Small: 34.0 (#247)

Coding benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Coding14081362
SciCode—26.5%
BigCodeBench Instruct—36.1%
LiveBench Coding—36.2%
BigCodeBench Complete—46.6%
ALE-Bench—497.62

Agentic & Tool Use Not comparable

GPT-5.3 Chat: —, Mistral Small: 28.1 (#93)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.3 ChatMistral Small
Berkeley Function Calling Leaderboard—37.1%

Reasoning GPT-5.3 Chat leads

GPT-5.3 Chat: 28.5 (#102), Mistral Small: 19.8 (#250)

Reasoning benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Hard Prompts13991335
Kagi LLM Benchmark—37.8%
CritPt—0%
LiveBench Reasoning—44.8%
DTBench—70.9%
LiveBench Data Analysis—53.7%
LMCA—20.6%
LiveBench—44%

Math GPT-5.3 Chat leads

GPT-5.3 Chat: 38.2 (#142), Mistral Small: 16.4 (#293)

Math benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Math13891341
OTIS Mock AIME 2024-2025—5.8%
LiveBench Math—39.9%
MATH Level 5—46.8%

Knowledge GPT-5.3 Chat leads

GPT-5.3 Chat: 38.8 (#140), Mistral Small: 31.0 (#222)

Knowledge benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Expert13971291
GPQA Diamond—47.5%
Vectara Hallucination Rate—5.1%
MMLU—68.7%

Multimodal Not comparable

GPT-5.3 Chat: —, Mistral Small: 33.5 (#96)

Multimodal benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Vision—1142

Multilingual GPT-5.3 Chat leads

GPT-5.3 Chat: 50.3 (#124), Mistral Small: 45.5 (#169)

Multilingual benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Non-English13821315
LMArena Chinese14321340
LMArena French13971337
LMArena German13841340
LMArena Japanese13521275
LMArena Korean13461259
LMArena Russian14001324
LMArena Spanish13711346

Instruction Following GPT-5.3 Chat leads

GPT-5.3 Chat: 72.8 (#129), Mistral Small: 66.4 (#209)

Instruction Following benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Instruction Following13781310
LiveBench Instruction Following—63.7%

Long Context GPT-5.3 Chat leads

GPT-5.3 Chat: 42.6 (#120), Mistral Small: 40.4 (#156)

Long Context benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Longer Query13961327

Writing & Preference GPT-5.3 Chat leads

GPT-5.3 Chat: 63.1 (#68), Mistral Small: 52.5 (#171)

Writing & Preference benchmarks
BenchmarkGPT-5.3 ChatMistral Small
LMArena Text13891338
LMArena Creative Writing13551305
LMArena Multi-Turn14121344
EQ-Bench Creative Writing1690—
LiveBench Language—30.5%

Frequently asked questions

Is GPT-5.3 Chat better than Mistral Small?

GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 33.4 on the Noometry Index. Mistral Small costs 18× 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?

Mistral Small is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

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

GPT-5.3 Chat scores higher on coding benchmarks: 41.4 versus 34.0 in the Noometry coding category.

Which has the bigger context window?

Mistral Small does, with 262K tokens against 128K.

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

17 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Mistral Small has 39.

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