Noometry

Model comparison

Gemini 3.1 Pro Preview vs GPT-6 Luna

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 45.1 on the Noometry Index. GPT-6 Luna costs 23× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

Last verified . 17 shared benchmarks.

Gemini 3.1 Pro Preview Google

56.7

Rank #20 Confirmed

GPT-6 Luna OpenAI

45.1

Rank #65 Confirmed

Summary

  • They share 17 benchmarks with published results for both. Gemini 3.1 Pro Preview scores higher in 7 categories and GPT-6 Luna in 2 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.1 Pro Preview leads 71.7 to 31.7.
  • The biggest single-benchmark swing is DeepSWE: 11.7% for Gemini 3.1 Pro Preview and 66.6% for GPT-6 Luna.
  • GPT-6 Luna is cheaper at $0.10 / $0.50 per million input/output tokens, against $2 / $12 for Gemini 3.1 Pro Preview.
  • GPT-6 Luna accepts more context: 1.05M tokens versus 1.05M.

Side by side

Gemini 3.1 Pro PreviewGPT-6 Luna
ProviderGoogleOpenAI
Noometry Index56.745.1
Released2026-02-192026-09-22
WeightsProprietaryProprietary
Context window1.05M1.05M
Max output66K128K
Input $ / M tokens$2$0.10
Output $ / M tokens$12$0.50
Results tracked7118

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Category by category

Coding GPT-6 Luna leads

Gemini 3.1 Pro Preview: 42.7 (#88), GPT-6 Luna: 54.7 (#24)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
DeepSWE11.7%66.6%
LMArena WebDev14461583
LMArena Coding14831448
SWE-bench Verified75.6%—
FrontierCode—42.4%
SciCode58.9%—
GSO22.6%—
WeirdML72.1%—
MirrorCode8.9%—
ALE-Bench1,161—
AlgoTune2.02—

Agentic & Tool Use Not comparable

Gemini 3.1 Pro Preview: 37.7 (#33), GPT-6 Luna: —

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
Terminal-Bench80.2%—
APEX-Agents35.3%—
τ²-bench Banking26%—
DeepResearch Bench47.8%—
PostTrainBench22%—
BALROG57%—
ExploitBench26.1%—
GBAEval0.8%—
GDP.pdf17%—
LMArena Search1211—
METR Time Horizons77%—
Vending-Bench 23,774—

Reasoning Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 71.7 (#9), GPT-6 Luna: 31.7 (#68)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
NYT Connections (extended)97.4%68.7%
LMArena Hard Prompts14841415
ARC-AGI-277.1%—
SimpleBench79.6%—
ARC-AGI-198%—
CritPt17.7%—
Chess Puzzles55%—
EnigmaEval36.8%—
Thematic Generalization79.4%—
EBR-Bench14.3%—
Mystery Game Puzzles34%—
DTBench97.1%—
LMCA53.8%—
Epoch Capabilities Index154.92—
ForecastBench59—

Math Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 61.8 (#28), GPT-6 Luna: 35.6 (#140)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
LMArena Math14851396
FrontierMath (Tiers 1-3)59.6%—
FrontierMath Tier 426.8%—
MathArena Final-Answer Competitions86.5%—
OTIS Mock AIME 2024-202595.6%—
ProofBench26%—
FrontierMath (Feb 2025 set)36.9%—
FrontierMath Tier 4 (v1)16.7%—

Knowledge Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 71.8 (#3), GPT-6 Luna: 40.1 (#110)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
LMArena Expert14841458
GPQA Diamond94.4%—
Humanity's Last Exam46.4%—
SimpleQA Verified73.5%—
Vectara Hallucination Rate10.4%—

Multimodal GPT-6 Luna leads

Gemini 3.1 Pro Preview: 38.1 (#60), GPT-6 Luna: 42.0 (#27)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
Furniture Assembly26.7%44.2%
LMArena Vision1296—
Blueprint-Bench 226.5%—
LMArena Document1444—

Multilingual Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 57.1 (#11), GPT-6 Luna: 51.0 (#111)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
LMArena Non-English14751390
LMArena Chinese15281425
LMArena Russian14961392
LMArena Spanish14801416
LMArena French1488—
LMArena German1491—
LMArena Japanese1494—
LMArena Korean1458—

Instruction Following Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 77.1 (#31), GPT-6 Luna: 74.7 (#85)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
LMArena Instruction Following14651414

Long Context Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 47.3 (#17), GPT-6 Luna: 43.3 (#95)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
LMArena Longer Query14821417
CL-bench20.8%—
CL-bench Life16.9%—

Writing & Preference Gemini 3.1 Pro Preview leads

Gemini 3.1 Pro Preview: 66.3 (#36), GPT-6 Luna: 58.4 (#115)

BenchmarkGemini 3.1 Pro PreviewGPT-6 Luna
LMArena Text14801392
LMArena Creative Writing14821357
LMArena Multi-Turn14861400
EQ-Bench Creative Writing1491—
EQ-Bench 41142—

Frequently asked questions

Is Gemini 3.1 Pro Preview better than GPT-6 Luna?

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 45.1 on the Noometry Index. GPT-6 Luna costs 23× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

Which is cheaper, Gemini 3.1 Pro Preview or GPT-6 Luna?

GPT-6 Luna is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; Gemini 3.1 Pro Preview lists at $2 and $12.

Is Gemini 3.1 Pro Preview or GPT-6 Luna better for coding?

GPT-6 Luna scores higher on coding benchmarks: 54.7 versus 42.7 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Luna does, with 1.05M tokens against 1.05M.

How many benchmarks do Gemini 3.1 Pro Preview and GPT-6 Luna share?

17 benchmarks have published results for both models. Gemini 3.1 Pro Preview has 71 scored results on Noometry and GPT-6 Luna has 18.

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