Model comparison

GPT-5.5 Instant vs Mistral Medium

GPT-5.5 Instant is the stronger model overall, scoring 42.5 to 36.0 on the Noometry Index.

Last verified . 22 shared benchmarks.

GPT-5.5 Instant OpenAI

42.5

Rank #99 Confirmed

Mistral Medium Mistral AI

36.0

Rank #211 Confirmed

Summary

  • They share 22 benchmarks with published results for both. GPT-5.5 Instant scores higher in 8 categories and Mistral Medium in 1 category; 5 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where GPT-5.5 Instant leads 48.9 to 24.9.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 68.1% for GPT-5.5 Instant and 32.2% for Mistral Medium.
  • Mistral Medium has downloadable open weights; the other is API-only.

Side by side

GPT-5.5 Instant and Mistral Medium specifications
GPT-5.5 InstantMistral Medium
ProviderOpenAIMistral AI
Noometry Index42.536.0
Released2026-05-052023-12-11
WeightsProprietaryOpen
Context window—262K
Max output—262K
Input $ / M tokens—$1.50
Output $ / M tokens—$7.50
Results tracked2736

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding GPT-5.5 Instant leads

GPT-5.5 Instant: 43.7 (#73), Mistral Medium: 33.8 (#241)

Coding benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
SciCode48.6%40.2%
LMArena Coding14331434
FrontierCode—8%
WeirdML—43.7%
ALE-Bench—763.98

Agentic & Tool Use Not comparable

GPT-5.5 Instant: —, Mistral Medium: 28.1 (#84)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
Berkeley Function Calling Leaderboard—37.7%

Reasoning Too close to call

GPT-5.5 Instant: 24.2 (#149), Mistral Medium: 23.3 (#165)

Reasoning benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
CritPt0%0%
LMArena Hard Prompts14261426
Kagi LLM Benchmark—50%
Chess Puzzles12%—
DTBench—75.5%
LMCA—26.1%
Surface Evolver Bench—26.9%
Epoch Capabilities Index142.48—

Math Mistral Medium leads

GPT-5.5 Instant: 26.1 (#241), Mistral Medium: 27.2 (#238)

Math benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
OTIS Mock AIME 2024-202568.1%32.2%
LMArena Math14201409
FrontierMath (Tiers 1-3)26.3%—
FrontierMath Tier 42.4%—
ProofBench—9%
MATH Level 5—81.6%
FrontierMath (Feb 2025 set)—0.3%

Knowledge GPT-5.5 Instant leads

GPT-5.5 Instant: 48.9 (#68), Mistral Medium: 24.9 (#260)

Knowledge benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
GPQA Diamond82.5%59.5%
LMArena Expert14091408
Humanity's Last Exam—4.5%
Vectara Hallucination Rate—22.7%

Multimodal GPT-5.5 Instant leads

GPT-5.5 Instant: 39.3 (#48), Mistral Medium: 34.6 (#82)

Multimodal benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
LMArena Vision12501172
LMArena Document1403—

Multilingual Too close to call

GPT-5.5 Instant: 53.0 (#76), Mistral Medium: 52.3 (#86)

Multilingual benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
LMArena Non-English14171408
LMArena Chinese14571448
LMArena French14281460
LMArena German14101433
LMArena Japanese14081378
LMArena Korean13931382
LMArena Russian14301411
LMArena Spanish14301433

Instruction Following Too close to call

GPT-5.5 Instant: 74.4 (#94), Mistral Medium: 73.9 (#111)

Instruction Following benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
LMArena Instruction Following14071398

Long Context Too close to call

GPT-5.5 Instant: 43.4 (#92), Mistral Medium: 42.9 (#108)

Long Context benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
LMArena Longer Query14221406

Writing & Preference GPT-5.5 Instant leads

GPT-5.5 Instant: 62.0 (#81), Mistral Medium: 60.2 (#97)

Writing & Preference benchmarks
BenchmarkGPT-5.5 InstantMistral Medium
LMArena Text14191424
LMArena Creative Writing14201391
LMArena Multi-Turn14341418
Short-Story Creative Writing—77.3%

Frequently asked questions

Is GPT-5.5 Instant better than Mistral Medium?

GPT-5.5 Instant is the stronger model overall, scoring 42.5 to 36.0 on the Noometry Index.

Is GPT-5.5 Instant or Mistral Medium better for coding?

GPT-5.5 Instant scores higher on coding benchmarks: 43.7 versus 33.8 in the Noometry coding category.

How many benchmarks do GPT-5.5 Instant and Mistral Medium share?

22 benchmarks have published results for both models. GPT-5.5 Instant has 27 scored results on Noometry and Mistral Medium has 36.

Related comparisons

Go deeper