Model comparison

GPT-5 Nano vs o3-mini

o3-mini is the stronger model overall, scoring 36.7 to 33.5 on the Noometry Index. GPT-5 Nano costs 14× less per token, which makes it the better buy when o3-mini's lead doesn't matter for your workload.

Last verified . 34 shared benchmarks.

GPT-5 Nano OpenAI

33.5

Rank #241 Confirmed

o3-mini OpenAI

36.7

Rank #212 Confirmed

Summary

  • They share 34 benchmarks with published results for both. GPT-5 Nano scores higher in 1 category and o3-mini in 8 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where o3-mini leads 50.3 to 39.1.
  • The biggest single-benchmark swing is ARC-AGI-1: 20.7% for GPT-5 Nano and 34.5% for o3-mini.
  • GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $1.10 / $4.40 for o3-mini.
  • GPT-5 Nano accepts more context: 400K tokens versus 200K.

Side by side

GPT-5 Nano and o3-mini specifications
GPT-5 Nanoo3-mini
ProviderOpenAIOpenAI
Noometry Index33.536.7
Released2025-08-072024-12-20
WeightsProprietaryProprietary
Context window400K200K
Max output128K100K
Input $ / M tokens$0.05$1.10
Output $ / M tokens$0.40$4.40
Results tracked4951

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

Category by category

Coding o3-mini leads

GPT-5 Nano: 33.6 (#254), o3-mini: 40.8 (#132)

Coding benchmarks
BenchmarkGPT-5 Nanoo3-mini
WeirdML38.1%43.7%
LMArena Coding13511378
SWE-bench Verified (bash only)34.8%—
Aider Polyglot—60.4%
SciCode—39.8%
GSO—1.3%
LiveBench Coding—82.7%
CadEval—54%
ALE-Bench718.67—

Agentic & Tool Use o3-mini leads

GPT-5 Nano: 25.8 (#106), o3-mini: 29.6 (#84)

Agentic & Tool Use benchmarks
BenchmarkGPT-5 Nanoo3-mini
Terminal-Bench21.8%—
Berkeley Function Calling Leaderboard51.5%—
Cybench—22.5%

Reasoning Too close to call

GPT-5 Nano: 16.3 (#306), o3-mini: 16.3 (#305)

Reasoning benchmarks
BenchmarkGPT-5 Nanoo3-mini
ARC-AGI-22.6%3%
ARC-AGI-120.7%34.5%
Chess Puzzles27%17%
LMArena Hard Prompts13281366
Mystery Game Puzzles9%7%
DTBench62.7%68.8%
LMCA7.9%19%
Epoch Capabilities Index139.38140.34
ForecastBench59.159.6
SimpleBench—22.8%
Kagi LLM Benchmark62.2%—
CritPt—0.3%
LiveBench Reasoning—89.6%
LiveBench Data Analysis—70.6%
LiveBench—75.9%

Math GPT-5 Nano leads

GPT-5 Nano: 29.4 (#241), o3-mini: 28.1 (#244)

Math benchmarks
BenchmarkGPT-5 Nanoo3-mini
FrontierMath (Tiers 1-3)20%18.6%
FrontierMath Tier 42.4%0%
OTIS Mock AIME 2024-202581.1%76.9%
LMArena Math13171396
MATH Level 595.2%96.5%
FrontierMath (Feb 2025 set)8.3%12.4%
FrontierMath Tier 4 (v1)2.1%4.2%
ProofBench12%—
Omni-MATH54.6%—
LiveBench Math—77.3%

Knowledge o3-mini leads

GPT-5 Nano: 35.9 (#178), o3-mini: 38.3 (#146)

Knowledge benchmarks
BenchmarkGPT-5 Nanoo3-mini
GPQA Diamond69.4%77%
SimpleQA Verified11.7%15.3%
LMArena Expert13211364
MMLU-Pro77.8%—
Confabulations—17.9%
Vectara Hallucination Rate10.5%—
GPQA (HELM)67.9%—

Multimodal Not comparable

GPT-5 Nano: 31.3 (#108), o3-mini: —

Multimodal benchmarks
BenchmarkGPT-5 Nanoo3-mini
LMArena Vision1159—
VPCT37.2%—

Multilingual Too close to call

GPT-5 Nano: 45.3 (#172), o3-mini: 45.7 (#164)

Multilingual benchmarks
BenchmarkGPT-5 Nanoo3-mini
LMArena Non-English13131319
LMArena Chinese13561379
LMArena German13271303
LMArena Japanese12261286
LMArena Korean12691314
LMArena Russian12961304
LMArena Spanish13601321
LMArena French—1334

Instruction Following Too close to call

GPT-5 Nano: 75.0 (#79), o3-mini: 75.1 (#72)

Instruction Following benchmarks
BenchmarkGPT-5 Nanoo3-mini
LMArena Instruction Following13061337
LiveBench Instruction Following—84.4%
IFEval93.2%—

Long Context o3-mini leads

GPT-5 Nano: 31.3 (#281), o3-mini: 33.8 (#256)

Long Context benchmarks
BenchmarkGPT-5 Nanoo3-mini
Fiction.LiveBench44.4%50%
LMArena Longer Query13121343

Writing & Preference o3-mini leads

GPT-5 Nano: 39.1 (#249), o3-mini: 50.3 (#182)

Writing & Preference benchmarks
BenchmarkGPT-5 Nanoo3-mini
LMArena Text13201337
LMArena Creative Writing12491286
LMArena Multi-Turn13111320
Short-Story Creative Writing—61.7%
EQ-Bench Creative Writing705—
WildBench80.6%—
LiveBench Language—50.7%

Frequently asked questions

Is GPT-5 Nano better than o3-mini?

o3-mini is the stronger model overall, scoring 36.7 to 33.5 on the Noometry Index. GPT-5 Nano costs 14× less per token, which makes it the better buy when o3-mini's lead doesn't matter for your workload.

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

GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; o3-mini lists at $1.10 and $4.40.

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

o3-mini scores higher on coding benchmarks: 40.8 versus 33.6 in the Noometry coding category.

Which has the bigger context window?

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

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

34 benchmarks have published results for both models. GPT-5 Nano has 49 scored results on Noometry and o3-mini has 51.

Related comparisons

Go deeper