Model comparison

GPT-5.6 Luna vs GPT-5 Pro

GPT-5.6 Luna is the stronger model overall, scoring 54.6 to 46.4 on the Noometry Index.

Last verified . 8 shared benchmarks.

GPT-5.6 Luna OpenAI

54.6

Rank #30 Confirmed

GPT-5 Pro OpenAI

46.4

Rank #64 Confirmed

Summary

  • They share 8 benchmarks with published results for both. GPT-5.6 Luna scores higher in 4 categories and GPT-5 Pro in 0 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Luna leads 77.7 to 48.5.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 61% for GPT-5.6 Luna and 19.5% for GPT-5 Pro.
  • GPT-5.6 Luna is cheaper at $0.20 / $1.20 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
  • GPT-5.6 Luna accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5.6 Luna and GPT-5 Pro specifications
GPT-5.6 LunaGPT-5 Pro
ProviderOpenAIOpenAI
Noometry Index54.646.4
Released2026-07-092025-10-06
WeightsProprietaryProprietary
Context window1.05M400K
Max output128K272K
Input $ / M tokens$0.20$15
Output $ / M tokens$1.20$120
Results tracked5212

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

Category by category

Coding GPT-5.6 Luna leads

GPT-5.6 Luna: 54.5 (#28), GPT-5 Pro: 44.0 (#80)

Coding benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
WeirdML60.9%60.4%
DeepSWE67.2%—
FrontierCode39.8%—
CursorBench35.9%—
LMArena WebDev1519—
SciCode53.6%—
LMArena Coding1466—
ALE-Bench1,667—
AlgoTune—1.31

Agentic & Tool Use Not comparable

GPT-5.6 Luna: 34.4 (#45), GPT-5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
APEX-Agents43%—
BALROG45.6%—
GDP.pdf22.7%—
Vending-Bench 24,095—

Reasoning GPT-5.6 Luna leads

GPT-5.6 Luna: 47.6 (#43), GPT-5 Pro: 38.9 (#62)

Reasoning benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
ARC-AGI-259.5%18.3%
SimpleBench46.8%61.6%
Kagi LLM Benchmark49.1%76.8%
ARC-AGI-188%70.2%
Epoch Capabilities Index156.39150.28
NYT Connections (extended)69.4%—
CritPt20.6%—
Chess Puzzles40%—
EnigmaEval—18.8%
LMArena Hard Prompts1451—
Mystery Game Puzzles21%—
DTBench89.1%—
LMCA48.5%—
Surface Evolver Bench61.9%—

Math GPT-5.6 Luna leads

GPT-5.6 Luna: 77.7 (#14), GPT-5 Pro: 48.5 (#63)

Math benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
FrontierMath (Tiers 1-3)82.1%55.8%
FrontierMath Tier 461%19.5%
OTIS Mock AIME 2024-202598.3%—
ProofBench60%—
LMArena Math1458—
FrontierMath Tier 4 (v1)—14.6%

Knowledge GPT-5.6 Luna leads

GPT-5.6 Luna: 58.5 (#34), GPT-5 Pro: 56.7 (#42)

Knowledge benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
GPQA Diamond91.6%—
Humanity's Last Exam—31.6%
SimpleQA Verified41%—
LMArena Expert1478—

Multimodal Not comparable

GPT-5.6 Luna: 42.7 (#28), GPT-5 Pro: —

Multimodal benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
LMArena Vision1258—
Blueprint-Bench 222.6%—
Furniture Assembly42.5%—
LMArena Document1457—

Multilingual Not comparable

GPT-5.6 Luna: 52.8 (#78), GPT-5 Pro: —

Multilingual benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
LMArena Non-English1417—
LMArena Chinese1470—
LMArena French1456—
LMArena German1454—
LMArena Japanese1411—
LMArena Korean1415—
LMArena Russian1428—
LMArena Spanish1448—

Instruction Following Not comparable

GPT-5.6 Luna: 75.6 (#57), GPT-5 Pro: —

Instruction Following benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
LMArena Instruction Following1437—

Long Context Not comparable

GPT-5.6 Luna: 43.9 (#82), GPT-5 Pro: —

Long Context benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
LMArena Longer Query1436—

Writing & Preference Not comparable

GPT-5.6 Luna: 68.0 (#29), GPT-5 Pro: —

Writing & Preference benchmarks
BenchmarkGPT-5.6 LunaGPT-5 Pro
LMArena Text1431—
LMArena Creative Writing1396—
EQ-Bench Creative Writing1829—
EQ-Bench 41156—
LMArena Multi-Turn1434—

Frequently asked questions

Is GPT-5.6 Luna better than GPT-5 Pro?

GPT-5.6 Luna is the stronger model overall, scoring 54.6 to 46.4 on the Noometry Index.

Which is cheaper, GPT-5.6 Luna or GPT-5 Pro?

GPT-5.6 Luna is cheaper. It lists at $0.20 per million input tokens and $1.20 per million output tokens; GPT-5 Pro lists at $15 and $120.

Is GPT-5.6 Luna or GPT-5 Pro better for coding?

GPT-5.6 Luna scores higher on coding benchmarks: 54.5 versus 44.0 in the Noometry coding category.

Which has the bigger context window?

GPT-5.6 Luna does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5.6 Luna and GPT-5 Pro share?

8 benchmarks have published results for both models. GPT-5.6 Luna has 52 scored results on Noometry and GPT-5 Pro has 12.

Related comparisons

Go deeper