Model comparison

GPT-5.1 vs o3-mini

GPT-5.1 is the stronger model overall, scoring 49.0 to 36.7 on the Noometry Index. o3-mini costs 1.8× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 42 shared benchmarks.

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

o3-mini OpenAI

36.7

Rank #212 Confirmed

Summary

  • They share 42 benchmarks with published results for both. GPT-5.1 scores higher in 9 categories and o3-mini in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.1 leads 52.2 to 28.1.
  • The biggest single-benchmark swing is ARC-AGI-1: 72.8% for GPT-5.1 and 34.5% for o3-mini.
  • o3-mini is cheaper at $1.10 / $4.40 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • GPT-5.1 accepts more context: 400K tokens versus 200K.

Side by side

GPT-5.1 and o3-mini specifications
GPT-5.1o3-mini
ProviderOpenAIOpenAI
Noometry Index49.036.7
Released2025-11-132024-12-20
WeightsProprietaryProprietary
Context window400K200K
Max output128K100K
Input $ / M tokens$1.25$1.10
Output $ / M tokens$10$4.40
Results tracked6351

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

Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.4 (#66), o3-mini: 40.8 (#132)

Coding benchmarks
BenchmarkGPT-5.1o3-mini
SciCode43.3%39.8%
GSO13.7%1.3%
WeirdML60.8%43.7%
LiveBench Coding72.5%82.7%
LMArena Coding14541378
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
Aider Polyglot—60.4%
LMArena WebDev1395—
CadEval—54%
ALE-Bench1,192—

Agentic & Tool Use GPT-5.1 leads

GPT-5.1: 32.7 (#60), o3-mini: 29.6 (#84)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1o3-mini
Terminal-Bench47.6%—
Cybench—22.5%
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning GPT-5.1 leads

GPT-5.1: 39.8 (#58), o3-mini: 16.3 (#305)

Reasoning benchmarks
BenchmarkGPT-5.1o3-mini
ARC-AGI-217.6%3%
SimpleBench53.2%22.8%
ARC-AGI-172.8%34.5%
CritPt4.9%0.3%
Chess Puzzles32%17%
LiveBench Reasoning95.8%89.6%
LMArena Hard Prompts14571366
Mystery Game Puzzles19%7%
DTBench90.1%68.8%
LiveBench Data Analysis72.1%70.6%
LMCA43.9%19%
Epoch Capabilities Index149.64140.34
ForecastBench58.159.6
LiveBench78.8%75.9%
EnigmaEval11.2%—

Math GPT-5.1 leads

GPT-5.1: 52.2 (#51), o3-mini: 28.1 (#244)

Math benchmarks
BenchmarkGPT-5.1o3-mini
OTIS Mock AIME 2024-202588.6%76.9%
LiveBench Math94.5%77.3%
LMArena Math14471396
FrontierMath (Feb 2025 set)31%12.4%
FrontierMath Tier 4 (v1)12.5%4.2%
FrontierMath (Tiers 1-3)—18.6%
FrontierMath Tier 4—0%
Omni-MATH46.4%—
MATH Level 5—96.5%

Knowledge GPT-5.1 leads

GPT-5.1: 50.6 (#71), o3-mini: 38.3 (#146)

Knowledge benchmarks
BenchmarkGPT-5.1o3-mini
GPQA Diamond87.6%77%
SimpleQA Verified48%15.3%
LMArena Expert14701364
Humanity's Last Exam23.7%—
MMLU-Pro57.9%—
Confabulations—17.9%
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—

Multimodal Not comparable

GPT-5.1: 44.8 (#19), o3-mini: —

Multimodal benchmarks
BenchmarkGPT-5.1o3-mini
LMArena Vision1250—
VPCT58.7%—
LMArena Document1403—

Multilingual GPT-5.1 leads

GPT-5.1: 53.8 (#56), o3-mini: 45.7 (#164)

Multilingual benchmarks
BenchmarkGPT-5.1o3-mini
LMArena Non-English14311319
LMArena Chinese14951379
LMArena French14501334
LMArena German14381303
LMArena Japanese14531286
LMArena Korean14011314
LMArena Russian14351304
LMArena Spanish14331321

Instruction Following GPT-5.1 leads

GPT-5.1: 83.9 (#1), o3-mini: 75.1 (#72)

Instruction Following benchmarks
BenchmarkGPT-5.1o3-mini
LiveBench Instruction Following93.3%84.4%
LMArena Instruction Following14431337
IFEval93.5%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), o3-mini: 33.8 (#256)

Long Context benchmarks
BenchmarkGPT-5.1o3-mini
LMArena Longer Query14471343
Fiction.LiveBench—50%
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.5 (#55), o3-mini: 50.3 (#182)

Writing & Preference benchmarks
BenchmarkGPT-5.1o3-mini
LMArena Text14431337
LMArena Creative Writing14271286
LMArena Multi-Turn14501320
LiveBench Language80.2%50.7%
Short-Story Creative Writing—61.7%
WildBench86.3%—

Frequently asked questions

Is GPT-5.1 better than o3-mini?

GPT-5.1 is the stronger model overall, scoring 49.0 to 36.7 on the Noometry Index. o3-mini costs 1.8× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Which is cheaper, GPT-5.1 or o3-mini?

o3-mini is cheaper. It lists at $1.10 per million input tokens and $4.40 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is GPT-5.1 or o3-mini better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 40.8 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1 does, with 400K tokens against 200K.

How many benchmarks do GPT-5.1 and o3-mini share?

42 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and o3-mini has 51.

Related comparisons

Go deeper