Model comparison

Gemini 3.5 Flash vs GPT-5 Pro

Gemini 3.5 Flash is the stronger model overall, scoring 54.1 to 46.2 on the Noometry Index.

Last verified . 9 shared benchmarks.

Gemini 3.5 Flash Google

54.1

Rank #29 Confirmed

GPT-5 Pro OpenAI

46.2

Rank #58 Confirmed

Summary

  • They share 9 benchmarks with published results for both. Gemini 3.5 Flash scores higher in 4 categories and GPT-5 Pro in 0 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.5 Flash leads 62.7 to 39.2.
  • The biggest single-benchmark swing is ARC-AGI-2: 72.1% for Gemini 3.5 Flash and 18.3% for GPT-5 Pro.
  • Gemini 3.5 Flash is cheaper at $1.50 / $9 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
  • Gemini 3.5 Flash accepts more context: 1.05M tokens versus 400K.

Side by side

Gemini 3.5 Flash and GPT-5 Pro specifications
Gemini 3.5 FlashGPT-5 Pro
ProviderGoogleOpenAI
Noometry Index54.146.2
Released2026-05-192025-10-06
WeightsProprietaryProprietary
Context window1.05M400K
Max output66K272K
Input $ / M tokens$1.50$15
Output $ / M tokens$9$120
Results tracked5412

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Category by category

Coding Gemini 3.5 Flash leads

Gemini 3.5 Flash: 49.1 (#46), GPT-5 Pro: 43.4 (#77)

Coding benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
WeirdML62.6%60.4%
SWE-bench Verified79.3%—
DeepSWE37.4%—
LMArena WebDev1499—
SciCode53.1%—
LMArena Coding1492—
ALE-Bench911.02—
AlgoTune—1.31

Agentic & Tool Use Not comparable

Gemini 3.5 Flash: 24.8 (#107), GPT-5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
APEX-Agents27.5%—
GBAEval6.7%—
GDP.pdf14%—
Vending-Bench 25,396—

Reasoning Gemini 3.5 Flash leads

Gemini 3.5 Flash: 62.7 (#16), GPT-5 Pro: 39.2 (#52)

Reasoning benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
ARC-AGI-272.1%18.3%
SimpleBench76.7%61.6%
ARC-AGI-192.5%70.2%
EnigmaEval25.4%18.8%
Epoch Capabilities Index154.55150.26
Kagi LLM Benchmark—76.8%
NYT Connections (extended)92.6%—
CritPt13.1%—
Chess Puzzles50%—
EBR-Bench4.8%—
LMArena Hard Prompts1488—
Mystery Game Puzzles32%—
DTBench94.7%—
LMCA47.1%—
Surface Evolver Bench58.1%—
ForecastBench59—

Math Gemini 3.5 Flash leads

Gemini 3.5 Flash: 60.5 (#30), GPT-5 Pro: 48.0 (#53)

Knowledge Gemini 3.5 Flash leads

Gemini 3.5 Flash: 66.3 (#10), GPT-5 Pro: 56.2 (#39)

Knowledge benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
GPQA Diamond92.8%—
Humanity's Last Exam—31.6%
SimpleQA Verified66.2%—
LMArena Expert1493—

Multimodal Not comparable

Gemini 3.5 Flash: 45.7 (#13), GPT-5 Pro: —

Multimodal benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
LMArena Vision1311—
Blueprint-Bench 233.6%—
LMArena Document1463—

Multilingual Not comparable

Gemini 3.5 Flash: 57.1 (#12), GPT-5 Pro: —

Multilingual benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
LMArena Non-English1475—
LMArena Chinese1525—
LMArena French1490—
LMArena German1500—
LMArena Japanese1481—
LMArena Korean1453—
LMArena Russian1491—
LMArena Spanish1478—

Instruction Following Not comparable

Gemini 3.5 Flash: 77.2 (#29), GPT-5 Pro: —

Instruction Following benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
LMArena Instruction Following1466—

Long Context Not comparable

Gemini 3.5 Flash: 45.3 (#39), GPT-5 Pro: —

Long Context benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
LMArena Longer Query1481—

Writing & Preference Not comparable

Gemini 3.5 Flash: 65.5 (#46), GPT-5 Pro: —

Writing & Preference benchmarks
BenchmarkGemini 3.5 FlashGPT-5 Pro
LMArena Text1481—
LMArena Creative Writing1467—
EQ-Bench 41087—
LMArena Multi-Turn1482—

Frequently asked questions

Is Gemini 3.5 Flash better than GPT-5 Pro?

Gemini 3.5 Flash is the stronger model overall, scoring 54.1 to 46.2 on the Noometry Index.

Which is cheaper, Gemini 3.5 Flash or GPT-5 Pro?

Gemini 3.5 Flash is cheaper. It lists at $1.50 per million input tokens and $9 per million output tokens; GPT-5 Pro lists at $15 and $120.

Is Gemini 3.5 Flash or GPT-5 Pro better for coding?

Gemini 3.5 Flash scores higher on coding benchmarks: 49.1 versus 43.4 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.5 Flash does, with 1.05M tokens against 400K.

How many benchmarks do Gemini 3.5 Flash and GPT-5 Pro share?

9 benchmarks have published results for both models. Gemini 3.5 Flash has 54 scored results on Noometry and GPT-5 Pro has 12.

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