Model comparison

GPT-5.2 vs GPT-5.6 Luna

GPT-5.2 and GPT-5.6 Luna score almost the same on the Noometry Index (54.1 vs 54.6), so choose on price, context window or the category you care about most.

Last verified . 41 shared benchmarks.

GPT-5.2 OpenAI

54.1

Rank #34 Confirmed

GPT-5.6 Luna OpenAI

54.6

Rank #30 Confirmed

Summary

  • They share 41 benchmarks with published results for both. GPT-5.2 scores higher in 6 categories and GPT-5.6 Luna in 4 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Luna leads 77.7 to 60.0.
  • The biggest single-benchmark swing is ProofBench: 15% for GPT-5.2 and 60% for GPT-5.6 Luna.
  • GPT-5.6 Luna is cheaper at $0.20 / $1.20 per million input/output tokens, against $1.75 / $14 for GPT-5.2.
  • GPT-5.6 Luna accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5.2 and GPT-5.6 Luna specifications
GPT-5.2GPT-5.6 Luna
ProviderOpenAIOpenAI
Noometry Index54.154.6
Released2025-12-112026-07-09
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K128K
Input $ / M tokens$1.75$0.20
Output $ / M tokens$14$1.20
Results tracked6752

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Category by category

Coding GPT-5.6 Luna leads

GPT-5.2: 51.6 (#37), GPT-5.6 Luna: 54.5 (#28)

Coding benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
LMArena WebDev14161519
WeirdML72.2%60.9%
LMArena Coding14471466
ALE-Bench1,2941,667
SWE-bench Verified73.8%—
DeepSWE—67.2%
FrontierCode—39.8%
SWE-bench Verified (bash only)72.8%—
CursorBench—35.9%
SWE-bench Multilingual66.7%—
SciCode—53.6%
GSO27.4%—
AlgoTune2.05—

Agentic & Tool Use GPT-5.2 leads

GPT-5.2: 40.2 (#24), GPT-5.6 Luna: 34.4 (#45)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
Vending-Bench 23,5914,095
Terminal-Bench64.9%—
APEX-Agents—43%
Berkeley Function Calling Leaderboard55.9%—
GDPval49.7%—
Remote Labor Index2.5%—
τ²-bench Airline83%—
τ²-bench Banking32.2%—
τ²-bench Retail81.6%—
τ²-bench Telecom89.7%—
DeepResearch Bench41.1%—
BALROG—45.6%
GDP.pdf—22.7%
LMArena Search1207—
METR Time Horizons75.3%—

Reasoning GPT-5.2 leads

GPT-5.2: 50.2 (#35), GPT-5.6 Luna: 47.6 (#43)

Reasoning benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
ARC-AGI-252.9%59.5%
SimpleBench45.8%46.8%
Kagi LLM Benchmark73.3%49.1%
NYT Connections (extended)83.6%69.4%
ARC-AGI-186.2%88%
Chess Puzzles49%40%
LMArena Hard Prompts14451451
Mystery Game Puzzles23%21%
DTBench90.9%89.1%
LMCA43.9%48.5%
Epoch Capabilities Index153.45156.39
CritPt—20.6%
EnigmaEval10.4%—
EBR-Bench23%—
Surface Evolver Bench—61.9%
ForecastBench60.1—

Math GPT-5.6 Luna leads

GPT-5.2: 60.0 (#38), GPT-5.6 Luna: 77.7 (#14)

Knowledge Too close to call

GPT-5.2: 59.3 (#32), GPT-5.6 Luna: 58.5 (#34)

Knowledge benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
GPQA Diamond91.4%91.6%
SimpleQA Verified37.1%41%
LMArena Expert14451478
Humanity's Last Exam27.8%—
Vectara Hallucination Rate8.4%—

Multimodal GPT-5.2 leads

GPT-5.2: 51.3 (#7), GPT-5.6 Luna: 42.7 (#28)

Multimodal benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
LMArena Vision12681258
Furniture Assembly38.3%42.5%
LMArena Document14051457
VPCT84%—
Blueprint-Bench 2—22.6%

Multilingual Too close to call

GPT-5.2: 53.4 (#67), GPT-5.6 Luna: 52.8 (#78)

Multilingual benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
LMArena Non-English14251417
LMArena Chinese14601470
LMArena French14551456
LMArena German14481454
LMArena Japanese14201411
LMArena Korean13921415
LMArena Russian14401428
LMArena Spanish14331448

Instruction Following Too close to call

GPT-5.2: 74.7 (#89), GPT-5.6 Luna: 75.6 (#57)

Instruction Following benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
LMArena Instruction Following14171437

Long Context Too close to call

GPT-5.2: 44.0 (#78), GPT-5.6 Luna: 43.9 (#82)

Long Context benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
LMArena Longer Query14281436
CL-bench18.2%—

Writing & Preference GPT-5.6 Luna leads

GPT-5.2: 66.8 (#32), GPT-5.6 Luna: 68.0 (#29)

Writing & Preference benchmarks
BenchmarkGPT-5.2GPT-5.6 Luna
LMArena Text14391431
LMArena Creative Writing14011396
EQ-Bench Creative Writing17031829
LMArena Multi-Turn14581434
EQ-Bench 4—1156

Frequently asked questions

Is GPT-5.2 better than GPT-5.6 Luna?

GPT-5.2 and GPT-5.6 Luna score almost the same on the Noometry Index (54.1 vs 54.6), so choose on price, context window or the category you care about most.

Which is cheaper, GPT-5.2 or GPT-5.6 Luna?

GPT-5.6 Luna is cheaper. It lists at $0.20 per million input tokens and $1.20 per million output tokens; GPT-5.2 lists at $1.75 and $14.

Is GPT-5.2 or GPT-5.6 Luna better for coding?

GPT-5.6 Luna scores higher on coding benchmarks: 54.5 versus 51.6 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-5.2 and GPT-5.6 Luna share?

41 benchmarks have published results for both models. GPT-5.2 has 67 scored results on Noometry and GPT-5.6 Luna has 52.

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