Noometry

Model comparison

GPT-4.1 nano vs GPT-5.1

GPT-5.1 is the stronger model overall, scoring 48.8 to 27.7 on the Noometry Index. GPT-4.1 nano costs 20× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 32 shared benchmarks.

GPT-4.1 nano OpenAI

27.7

Rank #322 Confirmed

GPT-5.1 OpenAI

48.8

Rank #47 Confirmed

Summary

  • They share 32 benchmarks with published results for both. GPT-4.1 nano scores higher in 0 categories and GPT-5.1 in 10 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.1 leads 39.9 to 8.6.
  • The biggest single-benchmark swing is ARC-AGI-1: 0% for GPT-4.1 nano and 72.8% for GPT-5.1.
  • GPT-4.1 nano is cheaper at $0.10 / $0.40 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • GPT-4.1 nano accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-4.1 nanoGPT-5.1
ProviderOpenAIOpenAI
Noometry Index27.748.8
Released2025-04-142025-11-13
WeightsProprietaryProprietary
Context window1.05M400K
Max output33K128K
Input $ / M tokens$0.10$1.25
Output $ / M tokens$0.40$10
Results tracked3863

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Category by category

Coding GPT-5.1 leads

GPT-4.1 nano: 23.8 (#325), GPT-5.1: 46.9 (#59)

BenchmarkGPT-4.1 nanoGPT-5.1
SciCode25.9%43.3%
WeirdML19%60.8%
LMArena Coding13061454
SWE-bench Verified—68%
SWE-bench Verified (bash only)—66%
Aider Polyglot8.9%—
LMArena WebDev—1395
GSO—13.7%
LiveBench Coding—72.5%
ALE-Bench—1,192

Agentic & Tool Use GPT-5.1 leads

GPT-4.1 nano: 26.3 (#98), GPT-5.1: 32.5 (#55)

BenchmarkGPT-4.1 nanoGPT-5.1
Terminal-Bench—47.6%
Berkeley Function Calling Leaderboard33%—
DeepResearch Bench—42.8%
LMArena Search—1199
Vending-Bench 2—1,473

Reasoning GPT-5.1 leads

GPT-4.1 nano: 8.6 (#344), GPT-5.1: 39.9 (#50)

BenchmarkGPT-4.1 nanoGPT-5.1
ARC-AGI-20%17.6%
ARC-AGI-10%72.8%
CritPt0%4.9%
LMArena Hard Prompts12861457
DTBench52.5%90.1%
LMCA5.5%43.9%
Epoch Capabilities Index129.62149.66
SimpleBench—53.2%
Kagi LLM Benchmark33.3%—
Chess Puzzles—32%
EnigmaEval—11.2%
LiveBench Reasoning—95.8%
Mystery Game Puzzles—19%
LiveBench Data Analysis—72.1%
ForecastBench—58.1
LiveBench—78.8%

Math GPT-5.1 leads

GPT-4.1 nano: 25.5 (#246), GPT-5.1: 50.3 (#45)

BenchmarkGPT-4.1 nanoGPT-5.1
OTIS Mock AIME 2024-202528.9%88.6%
Omni-MATH36.7%46.4%
LMArena Math12741446
FrontierMath (Feb 2025 set)1%31%
LiveBench Math—94.5%
MATH Level 570%—
FrontierMath Tier 4 (v1)—12.5%

Knowledge GPT-5.1 leads

GPT-4.1 nano: 21.8 (#268), GPT-5.1: 50.5 (#65)

BenchmarkGPT-4.1 nanoGPT-5.1
GPQA Diamond48.9%87.6%
SimpleQA Verified6%48%
MMLU-Pro55%57.9%
GPQA (HELM)50.7%44.2%
LMArena Expert12721470
Humanity's Last Exam—23.7%
Vectara Hallucination Rate—10.9%

Multimodal GPT-5.1 leads

GPT-4.1 nano: 28.6 (#108), GPT-5.1: 44.0 (#17)

BenchmarkGPT-4.1 nanoGPT-5.1
LMArena Vision10631250
VPCT—58.7%
LMArena Document—1403

Multilingual GPT-5.1 leads

GPT-4.1 nano: 41.8 (#200), GPT-5.1: 54.0 (#51)

BenchmarkGPT-4.1 nanoGPT-5.1
LMArena Non-English12601431
LMArena Chinese12701495
LMArena German12881439
LMArena Japanese11991453
LMArena Russian12611435
LMArena French—1451
LMArena Korean—1401
LMArena Spanish—1430

Instruction Following GPT-5.1 leads

GPT-4.1 nano: 68.0 (#188), GPT-5.1: 84.0 (#1)

BenchmarkGPT-4.1 nanoGPT-5.1
IFEval84.3%93.5%
LMArena Instruction Following12671442
LiveBench Instruction Following—93.3%

Long Context GPT-5.1 leads

GPT-4.1 nano: 23.7 (#291), GPT-5.1: 47.6 (#14)

BenchmarkGPT-4.1 nanoGPT-5.1
LMArena Longer Query12831448
Fiction.LiveBench25%—
CL-bench—23.7%
CL-bench Life—17.3%

Writing & Preference GPT-5.1 leads

GPT-4.1 nano: 40.7 (#238), GPT-5.1: 64.7 (#53)

BenchmarkGPT-4.1 nanoGPT-5.1
LMArena Text12851443
LMArena Creative Writing12601427
WildBench81.2%86.3%
LMArena Multi-Turn12771449
EQ-Bench Creative Writing946—
LiveBench Language—80.2%

Frequently asked questions

Is GPT-4.1 nano better than GPT-5.1?

GPT-5.1 is the stronger model overall, scoring 48.8 to 27.7 on the Noometry Index. GPT-4.1 nano costs 20× 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-4.1 nano or GPT-5.1?

GPT-4.1 nano is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is GPT-4.1 nano or GPT-5.1 better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.9 versus 23.8 in the Noometry coding category.

Which has the bigger context window?

GPT-4.1 nano does, with 1.05M tokens against 400K.

How many benchmarks do GPT-4.1 nano and GPT-5.1 share?

32 benchmarks have published results for both models. GPT-4.1 nano has 38 scored results on Noometry and GPT-5.1 has 63.

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