Model comparison

GPT-5.1 vs o4-mini

GPT-5.1 is the stronger model overall, scoring 49.0 to 41.6 on the Noometry Index. o4-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 . 46 shared benchmarks.

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

o4-mini OpenAI

41.6

Rank #132 Confirmed

Summary

  • They share 46 benchmarks with published results for both. GPT-5.1 scores higher in 10 categories and o4-mini in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.1 leads 39.8 to 24.6.
  • The biggest single-benchmark swing is GPQA (HELM): 44.2% for GPT-5.1 and 73.5% for o4-mini.
  • o4-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 o4-mini specifications
GPT-5.1o4-mini
ProviderOpenAIOpenAI
Noometry Index49.041.6
Released2025-11-132025-04-16
WeightsProprietaryProprietary
Context window400K200K
Max output128K100K
Input $ / M tokens$1.25$1.10
Output $ / M tokens$10$4.40
Results tracked6360

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.4 (#66), o4-mini: 40.9 (#127)

Coding benchmarks
BenchmarkGPT-5.1o4-mini
SWE-bench Verified (bash only)66%45%
GSO13.7%3.6%
WeirdML60.8%52.6%
LMArena Coding14541368
ALE-Bench1,192826.17
SWE-bench Verified68%—
Aider Polyglot—72%
LMArena WebDev1395—
SciCode43.3%—
LiveBench Coding72.5%—
CadEval—62%
AlgoTune—1.72

Agentic & Tool Use Too close to call

GPT-5.1: 32.7 (#60), o4-mini: 32.6 (#61)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1o4-mini
Terminal-Bench47.6%—
Berkeley Function Calling Leaderboard—53.2%
GDPval—25.3%
DeepResearch Bench42.8%—
LMArena Search1199—
METR Time Horizons—63.9%
Vending-Bench 21,473—

Reasoning GPT-5.1 leads

GPT-5.1: 39.8 (#58), o4-mini: 24.6 (#162)

Reasoning benchmarks
BenchmarkGPT-5.1o4-mini
ARC-AGI-217.6%6.1%
SimpleBench53.2%38.7%
ARC-AGI-172.8%58.7%
CritPt4.9%0.6%
Chess Puzzles32%26%
EnigmaEval11.2%9.2%
LMArena Hard Prompts14571351
Mystery Game Puzzles19%5%
DTBench90.1%77.6%
LMCA43.9%26.5%
Epoch Capabilities Index149.64145.64
ForecastBench58.161.8
Kagi LLM Benchmark—67.6%
LiveBench Reasoning95.8%—
LiveBench Data Analysis72.1%—
LiveBench78.8%—

Math GPT-5.1 leads

GPT-5.1: 52.2 (#51), o4-mini: 40.8 (#89)

Math benchmarks
BenchmarkGPT-5.1o4-mini
OTIS Mock AIME 2024-202588.6%81.7%
Omni-MATH46.4%72%
LMArena Math14471389
FrontierMath (Feb 2025 set)31%24.8%
FrontierMath Tier 4 (v1)12.5%6.3%
FrontierMath (Tiers 1-3)—36.1%
FrontierMath Tier 4—4.9%
LiveBench Math94.5%—
MATH Level 5—97.8%

Knowledge GPT-5.1 leads

GPT-5.1: 50.6 (#71), o4-mini: 43.6 (#91)

Knowledge benchmarks
BenchmarkGPT-5.1o4-mini
GPQA Diamond87.6%79.6%
Humanity's Last Exam23.7%18.1%
SimpleQA Verified48%19.6%
MMLU-Pro57.9%82%
Vectara Hallucination Rate10.9%18.6%
GPQA (HELM)44.2%73.5%
LMArena Expert14701343
Confabulations—15.8%

Multimodal GPT-5.1 leads

GPT-5.1: 44.8 (#19), o4-mini: 40.2 (#49)

Multimodal benchmarks
BenchmarkGPT-5.1o4-mini
LMArena Vision12501194
VPCT58.7%57.5%
GeoBench—64%
LMArena Document1403—

Multilingual GPT-5.1 leads

GPT-5.1: 53.8 (#56), o4-mini: 47.0 (#154)

Multilingual benchmarks
BenchmarkGPT-5.1o4-mini
LMArena Non-English14311337
LMArena Chinese14951354
LMArena French14501364
LMArena German14381336
LMArena Japanese14531308
LMArena Korean14011312
LMArena Russian14351334
LMArena Spanish14331347

Instruction Following GPT-5.1 leads

GPT-5.1: 83.9 (#1), o4-mini: 75.2 (#68)

Instruction Following benchmarks
BenchmarkGPT-5.1o4-mini
IFEval93.5%92.8%
LMArena Instruction Following14431321
LiveBench Instruction Following93.3%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), o4-mini: 45.5 (#33)

Long Context benchmarks
BenchmarkGPT-5.1o4-mini
LMArena Longer Query14471315
Fiction.LiveBench—77.8%
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference GPT-5.1 leads

GPT-5.1: 64.5 (#55), o4-mini: 54.0 (#152)

Writing & Preference benchmarks
BenchmarkGPT-5.1o4-mini
LMArena Text14431353
LMArena Creative Writing14271294
WildBench86.3%85.4%
LMArena Multi-Turn14501350
Short-Story Creative Writing—75%
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than o4-mini?

GPT-5.1 is the stronger model overall, scoring 49.0 to 41.6 on the Noometry Index. o4-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 o4-mini?

o4-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 o4-mini better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 40.9 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 o4-mini share?

46 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and o4-mini has 60.

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