Noometry

Model comparison

Gemini 3.6 Flash vs GPT-5.1-Codex

Gemini 3.6 Flash is the stronger model overall, scoring 54.1 to 38.2 on the Noometry Index.

Last verified . 3 shared benchmarks.

Gemini 3.6 Flash Google

54.1

Rank #30 Confirmed

GPT-5.1-Codex OpenAI

38.2

Rank #178 Reported

Summary

  • They share 3 benchmarks with published results for both. Gemini 3.6 Flash scores higher in 2 categories and GPT-5.1-Codex in 1 category; 3 gaps are clear of the uncertainty.
  • The widest gap is in math, where Gemini 3.6 Flash leads 57.0 to 29.3.
  • The biggest single-benchmark swing is ProofBench: 36% for Gemini 3.6 Flash and 9% for GPT-5.1-Codex.
  • Gemini 3.6 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
  • Gemini 3.6 Flash accepts more context: 1.05M tokens versus 400K.

Side by side

Gemini 3.6 FlashGPT-5.1-Codex
ProviderGoogleOpenAI
Noometry Index54.138.2
Released2026-07-212025-11-12
WeightsProprietaryProprietary
Context window1.05M400K
Max output66K128K
Input $ / M tokens$0.75$1.25
Output $ / M tokens$3.75$10
Results tracked466

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Category by category

Coding Gemini 3.6 Flash leads

Gemini 3.6 Flash: 49.6 (#45), GPT-5.1-Codex: 41.7 (#107)

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
LMArena WebDev15361337
ALE-Bench715.521,245
DeepSWE46.7%—
FrontierCode34.4%—
SWE-bench Verified (bash only)—66%
SciCode52.7%—
WeirdML56.1%—
LMArena Coding1492—

Agentic & Tool Use GPT-5.1-Codex leads

Gemini 3.6 Flash: 32.4 (#56), GPT-5.1-Codex: 37.8 (#32)

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
Terminal-Bench—60.4%
APEX-Agents46.9%—
GDP.pdf14%—
METR Time Horizons—70.8%

Reasoning Not comparable

Gemini 3.6 Flash: 58.9 (#20), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
ARC-AGI-260.4%—
NYT Connections (extended)89%—
ARC-AGI-191.2%—
CritPt10.6%—
Chess Puzzles43%—
LMArena Hard Prompts1486—
Mystery Game Puzzles30%—
DTBench95.5%—
LMCA44.9%—
Epoch Capabilities Index154.36—

Math Gemini 3.6 Flash leads

Gemini 3.6 Flash: 57.0 (#33), GPT-5.1-Codex: 29.3 (#218)

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
ProofBench36%9%
FrontierMath (Tiers 1-3)58.9%—
FrontierMath Tier 422%—
MathArena Final-Answer Competitions70.8%—
OTIS Mock AIME 2024-202594.2%—
LMArena Math1504—

Knowledge Not comparable

Gemini 3.6 Flash: 67.8 (#7), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
GPQA Diamond94.1%—
SimpleQA Verified66.2%—
LMArena Expert1489—

Multimodal Not comparable

Gemini 3.6 Flash: 38.7 (#55), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
LMArena Vision1297—
Blueprint-Bench 231.2%—
Furniture Assembly23.3%—
LMArena Document1456—

Multilingual Not comparable

Gemini 3.6 Flash: 56.8 (#17), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
LMArena Non-English1470—
LMArena Chinese1530—
LMArena French1501—
LMArena German1478—
LMArena Japanese1477—
LMArena Korean1435—
LMArena Russian1490—
LMArena Spanish1477—

Instruction Following Not comparable

Gemini 3.6 Flash: 77.2 (#27), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
LMArena Instruction Following1467—

Long Context Not comparable

Gemini 3.6 Flash: 45.1 (#47), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
LMArena Longer Query1475—

Writing & Preference Not comparable

Gemini 3.6 Flash: 68.3 (#26), GPT-5.1-Codex: —

BenchmarkGemini 3.6 FlashGPT-5.1-Codex
LMArena Text1478—
LMArena Creative Writing1464—
EQ-Bench Creative Writing1604—
LMArena Multi-Turn1481—

Frequently asked questions

Is Gemini 3.6 Flash better than GPT-5.1-Codex?

Gemini 3.6 Flash is the stronger model overall, scoring 54.1 to 38.2 on the Noometry Index.

Which is cheaper, Gemini 3.6 Flash or GPT-5.1-Codex?

Gemini 3.6 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

Is Gemini 3.6 Flash or GPT-5.1-Codex better for coding?

Gemini 3.6 Flash scores higher on coding benchmarks: 49.6 versus 41.7 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.6 Flash does, with 1.05M tokens against 400K.

How many benchmarks do Gemini 3.6 Flash and GPT-5.1-Codex share?

3 benchmarks have published results for both models. Gemini 3.6 Flash has 46 scored results on Noometry and GPT-5.1-Codex has 6.

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