Model comparison

GPT-5 Mini vs o3-mini

GPT-5 Mini is the stronger model overall, scoring 41.8 to 36.7 on the Noometry Index.

Last verified . 39 shared benchmarks.

GPT-5 Mini OpenAI

41.8

Rank #128 Confirmed

o3-mini OpenAI

36.7

Rank #212 Confirmed

Summary

  • They share 39 benchmarks with published results for both. GPT-5 Mini scores higher in 8 categories and o3-mini in 1 category; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5 Mini leads 46.7 to 28.1.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 46.7% for GPT-5 Mini and 18.6% for o3-mini.
  • GPT-5 Mini is cheaper at $0.25 / $2 per million input/output tokens, against $1.10 / $4.40 for o3-mini.
  • GPT-5 Mini accepts more context: 400K tokens versus 200K.

Side by side

GPT-5 Mini and o3-mini specifications
GPT-5 Minio3-mini
ProviderOpenAIOpenAI
Noometry Index41.836.7
Released2025-08-072024-12-20
WeightsProprietaryProprietary
Context window400K200K
Max output128K100K
Input $ / M tokens$0.25$1.10
Output $ / M tokens$2$4.40
Results tracked6051

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Category by category

Coding Too close to call

GPT-5 Mini: 40.1 (#146), o3-mini: 40.8 (#132)

Coding benchmarks
BenchmarkGPT-5 Minio3-mini
SciCode39.2%39.8%
WeirdML52.7%43.7%
LMArena Coding14061378
SWE-bench Verified64.7%—
SWE-bench Verified (bash only)59.8%—
Aider Polyglot—60.4%
SWE-bench Multilingual39.7%—
GSO—1.3%
LiveBench Coding—82.7%
CadEval—54%
ALE-Bench799.77—
AlgoTune1.38—

Agentic & Tool Use GPT-5 Mini leads

GPT-5 Mini: 31.1 (#70), o3-mini: 29.6 (#84)

Agentic & Tool Use benchmarks
BenchmarkGPT-5 Minio3-mini
Terminal-Bench34.8%—
Berkeley Function Calling Leaderboard55.5%—
Cybench—22.5%
Vending-Bench 2-31.18—

Reasoning GPT-5 Mini leads

GPT-5 Mini: 23.9 (#168), o3-mini: 16.3 (#305)

Reasoning benchmarks
BenchmarkGPT-5 Minio3-mini
ARC-AGI-24.4%3%
ARC-AGI-154.3%34.5%
CritPt0%0.3%
Chess Puzzles30%17%
LMArena Hard Prompts13801366
Mystery Game Puzzles10%7%
DTBench80.5%68.8%
LMCA34.2%19%
Epoch Capabilities Index145.52140.34
ForecastBench6159.6
SimpleBench—22.8%
Kagi LLM Benchmark70.3%—
EnigmaEval8.2%—
LiveBench Reasoning—89.6%
LiveBench Data Analysis—70.6%
LiveBench—75.9%

Math GPT-5 Mini leads

GPT-5 Mini: 46.7 (#69), o3-mini: 28.1 (#244)

Math benchmarks
BenchmarkGPT-5 Minio3-mini
FrontierMath (Tiers 1-3)46.7%18.6%
FrontierMath Tier 412.2%0%
OTIS Mock AIME 2024-202586.7%76.9%
LMArena Math13781396
MATH Level 597.8%96.5%
FrontierMath (Feb 2025 set)27.2%12.4%
FrontierMath Tier 4 (v1)6.3%4.2%
ProofBench9%—
Omni-MATH72.2%—
LiveBench Math—77.3%

Knowledge GPT-5 Mini leads

GPT-5 Mini: 45.6 (#86), o3-mini: 38.3 (#146)

Knowledge benchmarks
BenchmarkGPT-5 Minio3-mini
GPQA Diamond75%77%
SimpleQA Verified21.6%15.3%
Confabulations13.3%17.9%
LMArena Expert13791364
Humanity's Last Exam19.4%—
MMLU-Pro83.5%—
Vectara Hallucination Rate12.9%—
GPQA (HELM)75.6%—

Multimodal Not comparable

GPT-5 Mini: 35.6 (#85), o3-mini: —

Multimodal benchmarks
BenchmarkGPT-5 Minio3-mini
LMArena Vision1202—
VPCT40.2%—

Multilingual GPT-5 Mini leads

GPT-5 Mini: 48.9 (#137), o3-mini: 45.7 (#164)

Multilingual benchmarks
BenchmarkGPT-5 Minio3-mini
LMArena Non-English13631319
LMArena Chinese13851379
LMArena French13861334
LMArena German13661303
LMArena Japanese13411286
LMArena Korean13081314
LMArena Russian13621304
LMArena Spanish13551321

Instruction Following GPT-5 Mini leads

GPT-5 Mini: 76.2 (#46), o3-mini: 75.1 (#72)

Instruction Following benchmarks
BenchmarkGPT-5 Minio3-mini
LMArena Instruction Following13571337
LiveBench Instruction Following—84.4%
IFEval92.7%—

Long Context GPT-5 Mini leads

GPT-5 Mini: 41.9 (#132), o3-mini: 33.8 (#256)

Long Context benchmarks
BenchmarkGPT-5 Minio3-mini
Fiction.LiveBench69.4%50%
LMArena Longer Query13551343

Writing & Preference GPT-5 Mini leads

GPT-5 Mini: 55.2 (#148), o3-mini: 50.3 (#182)

Writing & Preference benchmarks
BenchmarkGPT-5 Minio3-mini
LMArena Text13731337
LMArena Creative Writing13251286
Short-Story Creative Writing83.1%61.7%
LMArena Multi-Turn13631320
EQ-Bench Creative Writing1313—
WildBench85.5%—
LiveBench Language—50.7%

Frequently asked questions

Is GPT-5 Mini better than o3-mini?

GPT-5 Mini is the stronger model overall, scoring 41.8 to 36.7 on the Noometry Index.

Which is cheaper, GPT-5 Mini or o3-mini?

GPT-5 Mini is cheaper. It lists at $0.25 per million input tokens and $2 per million output tokens; o3-mini lists at $1.10 and $4.40.

Is GPT-5 Mini or o3-mini better for coding?

They score almost the same on coding (40.1 vs 40.8); test both on your own repository before choosing.

Which has the bigger context window?

GPT-5 Mini does, with 400K tokens against 200K.

How many benchmarks do GPT-5 Mini and o3-mini share?

39 benchmarks have published results for both models. GPT-5 Mini has 60 scored results on Noometry and o3-mini has 51.

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