Model comparison

Gemini 3 Pro vs GPT-5.1-Codex

Gemini 3 Pro is the stronger model overall, scoring 54.7 to 38.2 on the Noometry Index.

Last verified . 6 shared benchmarks.

Gemini 3 Pro Google

54.7

Rank #23 Confirmed

GPT-5.1-Codex OpenAI

38.2

Rank #178 Reported

Summary

  • They share 6 benchmarks with published results for both. Gemini 3 Pro scores higher in 3 categories and GPT-5.1-Codex in 0 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in math, where Gemini 3 Pro leads 48.8 to 29.3.
  • The biggest single-benchmark swing is ProofBench: 20% for Gemini 3 Pro and 9% for GPT-5.1-Codex.

Side by side

Gemini 3 Pro and GPT-5.1-Codex specifications
Gemini 3 ProGPT-5.1-Codex
ProviderGoogleOpenAI
Noometry Index54.738.2
Released2025-11-182025-11-12
WeightsProprietaryProprietary
Context window—400K
Max output—128K
Input $ / M tokens—$1.25
Output $ / M tokens—$10
Results tracked676

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Category by category

Coding Gemini 3 Pro leads

Gemini 3 Pro: 52.1 (#33), GPT-5.1-Codex: 41.7 (#107)

Coding benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
SWE-bench Verified (bash only)74.2%66%
LMArena WebDev14391337
ALE-Bench1,1771,245
SWE-bench Verified72.9%—
SWE-bench Multilingual68.7%—
GSO18.6%—
WeirdML69.9%—
LMArena Coding1482—
AlgoTune1.83—

Agentic & Tool Use Gemini 3 Pro leads

Gemini 3 Pro: 40.5 (#21), GPT-5.1-Codex: 37.8 (#32)

Agentic & Tool Use benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
Terminal-Bench69.4%60.4%
METR Time Horizons71%70.8%
Berkeley Function Calling Leaderboard72.5%—
GDPval40.3%—
Remote Labor Index1.3%—
τ²-bench Airline80.5%—
τ²-bench Banking18%—
τ²-bench Retail75.9%—
τ²-bench Telecom91%—
DeepResearch Bench46.3%—
BALROG58.1%—
LMArena Search1207—
Vending-Bench 25,478—

Reasoning Not comparable

Gemini 3 Pro: 52.5 (#28), GPT-5.1-Codex: —

Reasoning benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
ARC-AGI-231.1%—
SimpleBench76.4%—
Kagi LLM Benchmark80.1%—
NYT Connections (extended)94.4%—
ARC-AGI-175%—
CritPt6.9%—
Chess Puzzles31%—
EnigmaEval18.2%—
LMArena Hard Prompts1481—
Epoch Capabilities Index152.96—
ForecastBench61.2—

Math Gemini 3 Pro leads

Gemini 3 Pro: 48.8 (#50), GPT-5.1-Codex: 29.3 (#218)

Math benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
ProofBench20%9%
MathArena Final-Answer Competitions67%—
OTIS Mock AIME 2024-202591.4%—
Omni-MATH55.5%—
LMArena Math1475—
FrontierMath (Feb 2025 set)37.6%—
FrontierMath Tier 4 (v1)18.8%—

Knowledge Not comparable

Gemini 3 Pro: 64.3 (#15), GPT-5.1-Codex: —

Knowledge benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
GPQA Diamond92.6%—
Humanity's Last Exam37.5%—
MMLU-Pro90.3%—
Vectara Hallucination Rate13.6%—
GPQA (HELM)80.3%—
LMArena Expert1475—

Multimodal Not comparable

Gemini 3 Pro: 56.9 (#1), GPT-5.1-Codex: —

Multimodal benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
LMArena Vision1305—
GeoBench84%—
VPCT91%—
LMArena Document1434—

Multilingual Not comparable

Gemini 3 Pro: 57.1 (#14), GPT-5.1-Codex: —

Multilingual benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
LMArena Non-English1474—
LMArena Chinese1522—
LMArena French1492—
LMArena German1517—
LMArena Japanese1513—
LMArena Korean1449—
LMArena Russian1493—
LMArena Spanish1468—

Instruction Following Not comparable

Gemini 3 Pro: 76.4 (#42), GPT-5.1-Codex: —

Instruction Following benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
IFEval87.7%—
LMArena Instruction Following1458—

Long Context Not comparable

Gemini 3 Pro: 44.0 (#75), GPT-5.1-Codex: —

Long Context benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
CL-bench15.8%—
LMArena Longer Query1472—

Writing & Preference Not comparable

Gemini 3 Pro: 66.6 (#34), GPT-5.1-Codex: —

Writing & Preference benchmarks
BenchmarkGemini 3 ProGPT-5.1-Codex
LMArena Text1479—
LMArena Creative Writing1482—
EQ-Bench Creative Writing1525—
WildBench85.9%—
LMArena Multi-Turn1484—

Frequently asked questions

Is Gemini 3 Pro better than GPT-5.1-Codex?

Gemini 3 Pro is the stronger model overall, scoring 54.7 to 38.2 on the Noometry Index.

Is Gemini 3 Pro or GPT-5.1-Codex better for coding?

Gemini 3 Pro scores higher on coding benchmarks: 52.1 versus 41.7 in the Noometry coding category.

How many benchmarks do Gemini 3 Pro and GPT-5.1-Codex share?

6 benchmarks have published results for both models. Gemini 3 Pro has 67 scored results on Noometry and GPT-5.1-Codex has 6.

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