Model comparison

GPT-5.6 Luna vs o3-pro

GPT-5.6 Luna is the stronger model overall, scoring 54.7 to 42.7 on the Noometry Index.

Last verified . 7 shared benchmarks.

GPT-5.6 Luna OpenAI

54.7

Rank #24 Confirmed

o3-pro OpenAI

42.7

Rank #94 Confirmed

Summary

  • They share 7 benchmarks with published results for both. GPT-5.6 Luna scores higher in 3 categories and o3-pro in 2 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where GPT-5.6 Luna leads 58.6 to 29.0.
  • The biggest single-benchmark swing is ARC-AGI-2: 59.5% for GPT-5.6 Luna and 4.9% for o3-pro.
  • GPT-5.6 Luna is cheaper at $0.20 / $1.20 per million input/output tokens, against $20 / $80 for o3-pro.
  • GPT-5.6 Luna accepts more context: 1.05M tokens versus 200K.

Side by side

GPT-5.6 Luna and o3-pro specifications
GPT-5.6 Lunao3-pro
ProviderOpenAIOpenAI
Noometry Index54.742.7
Released2026-07-092025-06-10
WeightsProprietaryProprietary
Context window1.05M200K
Max output128K100K
Input $ / M tokens$0.20$20
Output $ / M tokens$1.20$80
Results tracked5112

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Category by category

Coding o3-pro leads

GPT-5.6 Luna: 53.9 (#25), o3-pro: 55.1 (#22)

Coding benchmarks
BenchmarkGPT-5.6 Lunao3-pro
WeirdML60.9%58.2%
DeepSWE67.2%—
FrontierCode39.8%—
Aider Polyglot—84.9%
CursorBench35.9%—
LMArena WebDev1517—
SciCode53.6%—
LMArena Coding1466—
ALE-Bench1,667—

Agentic & Tool Use Not comparable

GPT-5.6 Luna: 35.3 (#37), o3-pro: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 Lunao3-pro
BALROG45.6%—
GDP.pdf22.7%—
Vending-Bench 24,095—

Reasoning GPT-5.6 Luna leads

GPT-5.6 Luna: 47.5 (#38), o3-pro: 24.1 (#152)

Reasoning benchmarks
BenchmarkGPT-5.6 Lunao3-pro
ARC-AGI-259.5%4.9%
Kagi LLM Benchmark49.1%72.1%
ARC-AGI-188%59.3%
DTBench89.1%86.9%
LMCA48.5%38.5%
Epoch Capabilities Index156.32147.43
SimpleBench46.8%—
NYT Connections (extended)69.4%—
CritPt20.6%—
Chess Puzzles40%—
LMArena Hard Prompts1452—
Mystery Game Puzzles21%—
Surface Evolver Bench61.9%—

Math Not comparable

GPT-5.6 Luna: 77.5 (#12), o3-pro: —

Math benchmarks
BenchmarkGPT-5.6 Lunao3-pro
FrontierMath (Tiers 1-3)82.1%—
FrontierMath Tier 461%—
OTIS Mock AIME 2024-202598.3%—
ProofBench60%—
LMArena Math1455—

Knowledge GPT-5.6 Luna leads

GPT-5.6 Luna: 58.6 (#31), o3-pro: 29.0 (#234)

Knowledge benchmarks
BenchmarkGPT-5.6 Lunao3-pro
GPQA Diamond91.6%—
SimpleQA Verified41%—
Confabulations—14.2%
Vectara Hallucination Rate—23.3%
LMArena Expert1479—

Multimodal Not comparable

GPT-5.6 Luna: 43.0 (#22), o3-pro: —

Multimodal benchmarks
BenchmarkGPT-5.6 Lunao3-pro
LMArena Vision1259—
Blueprint-Bench 222.6%—
Furniture Assembly42.5%—
LMArena Document1457—

Multilingual Not comparable

GPT-5.6 Luna: 53.0 (#73), o3-pro: —

Multilingual benchmarks
BenchmarkGPT-5.6 Lunao3-pro
LMArena Non-English1418—
LMArena Chinese1469—
LMArena French1457—
LMArena German1459—
LMArena Japanese1416—
LMArena Korean1414—
LMArena Russian1428—
LMArena Spanish1445—

Instruction Following Not comparable

GPT-5.6 Luna: 76.0 (#48), o3-pro: —

Instruction Following benchmarks
BenchmarkGPT-5.6 Lunao3-pro
LMArena Instruction Following1440—

Long Context o3-pro leads

GPT-5.6 Luna: 43.9 (#78), o3-pro: 72.1 (#1)

Long Context benchmarks
BenchmarkGPT-5.6 Lunao3-pro
Fiction.LiveBench—97.2%
LMArena Longer Query1437—

Writing & Preference GPT-5.6 Luna leads

GPT-5.6 Luna: 68.3 (#27), o3-pro: 57.1 (#128)

Writing & Preference benchmarks
BenchmarkGPT-5.6 Lunao3-pro
LMArena Text1432—
LMArena Creative Writing1397—
Short-Story Creative Writing—84.4%
EQ-Bench Creative Writing1829—
EQ-Bench 41156—
LMArena Multi-Turn1433—

Frequently asked questions

Is GPT-5.6 Luna better than o3-pro?

GPT-5.6 Luna is the stronger model overall, scoring 54.7 to 42.7 on the Noometry Index.

Which is cheaper, GPT-5.6 Luna or o3-pro?

GPT-5.6 Luna is cheaper. It lists at $0.20 per million input tokens and $1.20 per million output tokens; o3-pro lists at $20 and $80.

Is GPT-5.6 Luna or o3-pro better for coding?

o3-pro scores higher on coding benchmarks: 55.1 versus 53.9 in the Noometry coding category.

Which has the bigger context window?

GPT-5.6 Luna does, with 1.05M tokens against 200K.

How many benchmarks do GPT-5.6 Luna and o3-pro share?

7 benchmarks have published results for both models. GPT-5.6 Luna has 51 scored results on Noometry and o3-pro has 12.

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