Model comparison

GPT-5.1 vs GPT-5 Pro

GPT-5.1 is the stronger model overall, scoring 49.0 to 46.4 on the Noometry Index.

Last verified . 8 shared benchmarks.

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

GPT-5 Pro OpenAI

46.4

Rank #64 Confirmed

Summary

  • They share 8 benchmarks with published results for both. GPT-5.1 scores higher in 3 categories and GPT-5 Pro in 1 category; 3 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where GPT-5 Pro leads 56.7 to 50.6.
  • The biggest single-benchmark swing is SimpleBench: 53.2% for GPT-5.1 and 61.6% for GPT-5 Pro.
  • GPT-5.1 is cheaper at $1.25 / $10 per million input/output tokens, against $15 / $120 for GPT-5 Pro.

Side by side

GPT-5.1 and GPT-5 Pro specifications
GPT-5.1GPT-5 Pro
ProviderOpenAIOpenAI
Noometry Index49.046.4
Released2025-11-132025-10-06
WeightsProprietaryProprietary
Context window400K400K
Max output128K272K
Input $ / M tokens$1.25$15
Output $ / M tokens$10$120
Results tracked6312

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Category by category

Coding GPT-5.1 leads

GPT-5.1: 46.4 (#66), GPT-5 Pro: 44.0 (#80)

Coding benchmarks
BenchmarkGPT-5.1GPT-5 Pro
WeirdML60.8%60.4%
SWE-bench Verified68%—
SWE-bench Verified (bash only)66%—
LMArena WebDev1395—
SciCode43.3%—
GSO13.7%—
LiveBench Coding72.5%—
LMArena Coding1454—
ALE-Bench1,192—
AlgoTune—1.31

Agentic & Tool Use Not comparable

GPT-5.1: 32.7 (#60), GPT-5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1GPT-5 Pro
Terminal-Bench47.6%—
DeepResearch Bench42.8%—
LMArena Search1199—
Vending-Bench 21,473—

Reasoning Too close to call

GPT-5.1: 39.8 (#58), GPT-5 Pro: 38.9 (#62)

Reasoning benchmarks
BenchmarkGPT-5.1GPT-5 Pro
ARC-AGI-217.6%18.3%
SimpleBench53.2%61.6%
ARC-AGI-172.8%70.2%
EnigmaEval11.2%18.8%
Epoch Capabilities Index149.64150.28
Kagi LLM Benchmark—76.8%
CritPt4.9%—
Chess Puzzles32%—
LiveBench Reasoning95.8%—
LMArena Hard Prompts1457—
Mystery Game Puzzles19%—
DTBench90.1%—
LiveBench Data Analysis72.1%—
LMCA43.9%—
ForecastBench58.1—
LiveBench78.8%—

Math GPT-5.1 leads

GPT-5.1: 52.2 (#51), GPT-5 Pro: 48.5 (#63)

Math benchmarks
BenchmarkGPT-5.1GPT-5 Pro
FrontierMath Tier 4 (v1)12.5%14.6%
FrontierMath (Tiers 1-3)—55.8%
FrontierMath Tier 4—19.5%
OTIS Mock AIME 2024-202588.6%—
Omni-MATH46.4%—
LiveBench Math94.5%—
LMArena Math1447—
FrontierMath (Feb 2025 set)31%—

Knowledge GPT-5 Pro leads

GPT-5.1: 50.6 (#71), GPT-5 Pro: 56.7 (#42)

Knowledge benchmarks
BenchmarkGPT-5.1GPT-5 Pro
Humanity's Last Exam23.7%31.6%
GPQA Diamond87.6%—
SimpleQA Verified48%—
MMLU-Pro57.9%—
Vectara Hallucination Rate10.9%—
GPQA (HELM)44.2%—
LMArena Expert1470—

Multimodal Not comparable

GPT-5.1: 44.8 (#19), GPT-5 Pro: —

Multimodal benchmarks
BenchmarkGPT-5.1GPT-5 Pro
LMArena Vision1250—
VPCT58.7%—
LMArena Document1403—

Multilingual Not comparable

GPT-5.1: 53.8 (#56), GPT-5 Pro: —

Multilingual benchmarks
BenchmarkGPT-5.1GPT-5 Pro
LMArena Non-English1431—
LMArena Chinese1495—
LMArena French1450—
LMArena German1438—
LMArena Japanese1453—
LMArena Korean1401—
LMArena Russian1435—
LMArena Spanish1433—

Instruction Following Not comparable

GPT-5.1: 83.9 (#1), GPT-5 Pro: —

Instruction Following benchmarks
BenchmarkGPT-5.1GPT-5 Pro
LiveBench Instruction Following93.3%—
IFEval93.5%—
LMArena Instruction Following1443—

Long Context Not comparable

GPT-5.1: 47.6 (#14), GPT-5 Pro: —

Long Context benchmarks
BenchmarkGPT-5.1GPT-5 Pro
CL-bench23.7%—
CL-bench Life17.3%—
LMArena Longer Query1447—

Writing & Preference Not comparable

GPT-5.1: 64.5 (#55), GPT-5 Pro: —

Writing & Preference benchmarks
BenchmarkGPT-5.1GPT-5 Pro
LMArena Text1443—
LMArena Creative Writing1427—
WildBench86.3%—
LMArena Multi-Turn1450—
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than GPT-5 Pro?

GPT-5.1 is the stronger model overall, scoring 49.0 to 46.4 on the Noometry Index.

Which is cheaper, GPT-5.1 or GPT-5 Pro?

GPT-5.1 is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-5 Pro lists at $15 and $120.

Is GPT-5.1 or GPT-5 Pro better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.4 versus 44.0 in the Noometry coding category.

Which has the bigger context window?

Both accept 400K tokens.

How many benchmarks do GPT-5.1 and GPT-5 Pro share?

8 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and GPT-5 Pro has 12.

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