Model comparison

Gemini 3 Pro vs GPT-5-Codex

Gemini 3 Pro is the stronger model overall, scoring 54.8 to 37.9 on the Noometry Index.

Last verified . 3 shared benchmarks.

Gemini 3 Pro Google

54.8

Rank #28 Confirmed

GPT-5-Codex OpenAI

37.9

Rank #192 Reported

Summary

  • They share 3 benchmarks with published results for both. Gemini 3 Pro scores higher in 3 categories and GPT-5-Codex in 0 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3 Pro leads 52.5 to 30.9.
  • The biggest single-benchmark swing is Terminal-Bench: 69.4% for Gemini 3 Pro and 44.3% for GPT-5-Codex.

Side by side

Gemini 3 Pro and GPT-5-Codex specifications
Gemini 3 ProGPT-5-Codex
ProviderGoogleOpenAI
Noometry Index54.837.9
Released2025-11-182025-09-15
WeightsProprietaryProprietary
Context window—400K
Max output—128K
Input $ / M tokens—$1.25
Output $ / M tokens—$10
Results tracked673

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Category by category

Coding Gemini 3 Pro leads

Gemini 3 Pro: 51.6 (#39), GPT-5-Codex: 42.4 (#103)

Coding benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
WeirdML69.9%54.5%
SWE-bench Verified72.9%—
SWE-bench Verified (bash only)74.2%—
LMArena WebDev1440—
SWE-bench Multilingual68.7%—
GSO18.6%—
LMArena Coding1481—
ALE-Bench1,177—
AlgoTune1.83—

Agentic & Tool Use Gemini 3 Pro leads

Gemini 3 Pro: 40.6 (#23), GPT-5-Codex: 31.0 (#72)

Agentic & Tool Use benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
Terminal-Bench69.4%44.3%
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—
METR Time Horizons71%—
Vending-Bench 25,478—

Reasoning Gemini 3 Pro leads

Gemini 3 Pro: 52.5 (#31), GPT-5-Codex: 30.9 (#83)

Reasoning benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
Kagi LLM Benchmark80.1%70.3%
ARC-AGI-231.1%—
SimpleBench76.4%—
NYT Connections (extended)94.4%—
ARC-AGI-175%—
CritPt6.9%—
Chess Puzzles31%—
EnigmaEval18.2%—
LMArena Hard Prompts1480—
Epoch Capabilities Index152.92—
ForecastBench61.2—

Math Not comparable

Gemini 3 Pro: 49.9 (#59), GPT-5-Codex: —

Math benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
MathArena Final-Answer Competitions67%—
OTIS Mock AIME 2024-202591.4%—
ProofBench20%—
Omni-MATH55.5%—
LMArena Math1476—
FrontierMath (Feb 2025 set)37.6%—
FrontierMath Tier 4 (v1)18.8%—

Knowledge Not comparable

Gemini 3 Pro: 64.4 (#16), GPT-5-Codex: —

Knowledge benchmarks
BenchmarkGemini 3 ProGPT-5-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: 57.6 (#2), GPT-5-Codex: —

Multimodal benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
LMArena Vision1305—
GeoBench84%—
VPCT91%—
LMArena Document1434—

Multilingual Not comparable

Gemini 3 Pro: 56.9 (#16), GPT-5-Codex: —

Multilingual benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
LMArena Non-English1474—
LMArena Chinese1523—
LMArena French1492—
LMArena German1515—
LMArena Japanese1510—
LMArena Korean1448—
LMArena Russian1493—
LMArena Spanish1470—

Instruction Following Not comparable

Gemini 3 Pro: 76.3 (#45), GPT-5-Codex: —

Instruction Following benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
IFEval87.7%—
LMArena Instruction Following1458—

Long Context Not comparable

Gemini 3 Pro: 44.0 (#79), GPT-5-Codex: —

Long Context benchmarks
BenchmarkGemini 3 ProGPT-5-Codex
CL-bench15.8%—
LMArena Longer Query1471—

Writing & Preference Not comparable

Gemini 3 Pro: 66.4 (#35), GPT-5-Codex: —

Writing & Preference benchmarks
BenchmarkGemini 3 ProGPT-5-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-Codex?

Gemini 3 Pro is the stronger model overall, scoring 54.8 to 37.9 on the Noometry Index.

Is Gemini 3 Pro or GPT-5-Codex better for coding?

Gemini 3 Pro scores higher on coding benchmarks: 51.6 versus 42.4 in the Noometry coding category.

How many benchmarks do Gemini 3 Pro and GPT-5-Codex share?

3 benchmarks have published results for both models. Gemini 3 Pro has 67 scored results on Noometry and GPT-5-Codex has 3.

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