Noometry

Model comparison

Gemini 3.8 Flash vs GPT-5.3 Chat

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 42.8 on the Noometry Index.

Last verified . 18 shared benchmarks.

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

GPT-5.3 Chat OpenAI

42.8

Rank #109 Confirmed

Summary

  • They share 18 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 8 categories and GPT-5.3 Chat in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 28.5.
  • Gemini 3.8 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 128K.

Side by side

Gemini 3.8 FlashGPT-5.3 Chat
ProviderGoogleOpenAI
Noometry Index61.842.8
Released2026-09-022026-03-03
WeightsProprietaryProprietary
Context window1.05M128K
Max output66K16K
Input $ / M tokens$0.75$1.75
Output $ / M tokens$3.75$14
Results tracked5018

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Category by category

Coding Gemini 3.8 Flash leads

Gemini 3.8 Flash: 59.2 (#15), GPT-5.3 Chat: 41.4 (#124)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Coding15101408
DeepSWE73.8%—
FrontierCode41.2%—
CursorBench39.6%—
LMArena WebDev1584—
FrontierSWE19.6%—
SciCode56.6%—
WeirdML84.8%—
ALE-Bench1,270—

Agentic & Tool Use Not comparable

Gemini 3.8 Flash: 41.8 (#21), GPT-5.3 Chat: —

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
APEX-Agents64.3%—
Remote Labor Index5.8%—
GDP.pdf23.4%—
Vending-Bench 25,094—

Reasoning Gemini 3.8 Flash leads

Gemini 3.8 Flash: 76.9 (#5), GPT-5.3 Chat: 28.5 (#102)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Hard Prompts15081399
ARC-AGI-289.2%—
NYT Connections (extended)97.4%—
ARC-AGI-198.5%—
CritPt18.3%—
Chess Puzzles61%—
Mystery Game Puzzles47%—
DTBench95.7%—
LMCA52.9%—
Surface Evolver Bench76.9%—
Epoch Capabilities Index156.71—

Math Gemini 3.8 Flash leads

Gemini 3.8 Flash: 65.3 (#28), GPT-5.3 Chat: 38.2 (#142)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Math15281389
FrontierMath (Tiers 1-3)68.4%—
FrontierMath Tier 422%—
OTIS Mock AIME 2024-202598.9%—
ProofBench48%—

Knowledge Gemini 3.8 Flash leads

Gemini 3.8 Flash: 74.8 (#2), GPT-5.3 Chat: 38.8 (#140)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Expert15241397
GPQA Diamond95.4%—
Humanity's Last Exam44.5%—
SimpleQA Verified69.7%—

Multimodal Not comparable

Gemini 3.8 Flash: 40.7 (#45), GPT-5.3 Chat: —

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Vision1314—
Blueprint-Bench 238.6%—
Furniture Assembly31.7%—

Multilingual Gemini 3.8 Flash leads

Gemini 3.8 Flash: 58.0 (#5), GPT-5.3 Chat: 50.3 (#124)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Non-English14911382
LMArena Chinese15541432
LMArena French14981397
LMArena German14931384
LMArena Japanese15021352
LMArena Korean14591346
LMArena Russian15151400
LMArena Spanish14851371

Instruction Following Gemini 3.8 Flash leads

Gemini 3.8 Flash: 78.0 (#13), GPT-5.3 Chat: 72.8 (#129)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Instruction Following14901378

Long Context Gemini 3.8 Flash leads

Gemini 3.8 Flash: 46.3 (#24), GPT-5.3 Chat: 42.6 (#120)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Longer Query15081396

Writing & Preference Gemini 3.8 Flash leads

Gemini 3.8 Flash: 72.2 (#15), GPT-5.3 Chat: 63.1 (#68)

BenchmarkGemini 3.8 FlashGPT-5.3 Chat
LMArena Text14991389
LMArena Creative Writing14921355
EQ-Bench Creative Writing17481690
LMArena Multi-Turn15011412

Frequently asked questions

Is Gemini 3.8 Flash better than GPT-5.3 Chat?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 42.8 on the Noometry Index.

Which is cheaper, Gemini 3.8 Flash or GPT-5.3 Chat?

Gemini 3.8 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

Is Gemini 3.8 Flash or GPT-5.3 Chat better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 41.4 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 128K.

How many benchmarks do Gemini 3.8 Flash and GPT-5.3 Chat share?

18 benchmarks have published results for both models. Gemini 3.8 Flash has 50 scored results on Noometry and GPT-5.3 Chat has 18.

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