Noometry

Model comparison

Gemini 3.8 Flash vs GPT-5.5 Instant

Gemini 3.8 Flash is the stronger model overall, scoring 59.5 to 42.5 on the Noometry Index.

Last verified . 26 shared benchmarks.

Gemini 3.8 Flash Google

59.5

Rank #13 Confirmed

GPT-5.5 Instant OpenAI

42.5

Rank #99 Confirmed

Summary

  • They share 26 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 9 categories and GPT-5.5 Instant in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.8 Flash leads 64.7 to 24.2.
  • The biggest single-benchmark swing is Chess Puzzles: 61% for Gemini 3.8 Flash and 12% for GPT-5.5 Instant.

Side by side

Gemini 3.8 FlashGPT-5.5 Instant
ProviderGoogleOpenAI
Noometry Index59.542.5
Released2026-09-022026-05-05
WeightsProprietaryProprietary
Context window1.05M—
Max output66K—
Input $ / M tokens$0.75—
Output $ / M tokens$3.75—
Results tracked4627

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Category by category

Coding Gemini 3.8 Flash leads

Gemini 3.8 Flash: 56.4 (#17), GPT-5.5 Instant: 43.7 (#73)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
SciCode56.6%48.6%
LMArena Coding15121433
DeepSWE73.8%—
FrontierCode41.2%—
CursorBench39.6%—
LMArena WebDev1581—
FrontierSWE19.6%—
ALE-Bench1,270—

Agentic & Tool Use Not comparable

Gemini 3.8 Flash: 40.3 (#22), GPT-5.5 Instant: —

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
APEX-Agents64.3%—
GDP.pdf23.4%—
Vending-Bench 25,094—

Reasoning Gemini 3.8 Flash leads

Gemini 3.8 Flash: 64.7 (#13), GPT-5.5 Instant: 24.2 (#149)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
CritPt18.3%0%
Chess Puzzles61%12%
LMArena Hard Prompts15061426
Epoch Capabilities Index157.13142.48
NYT Connections (extended)97.4%—
Mystery Game Puzzles47%—
DTBench95.7%—
LMCA52.9%—
Surface Evolver Bench76.9%—

Math Gemini 3.8 Flash leads

Gemini 3.8 Flash: 65.2 (#22), GPT-5.5 Instant: 26.1 (#241)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
FrontierMath (Tiers 1-3)68.4%26.3%
FrontierMath Tier 422%2.4%
OTIS Mock AIME 2024-202598.9%68.1%
LMArena Math15281420
ProofBench48%—

Knowledge Gemini 3.8 Flash leads

Gemini 3.8 Flash: 74.9 (#2), GPT-5.5 Instant: 48.9 (#68)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
GPQA Diamond95.4%82.5%
LMArena Expert15291409
Humanity's Last Exam44.5%—
SimpleQA Verified69.7%—

Multimodal Gemini 3.8 Flash leads

Gemini 3.8 Flash: 40.9 (#33), GPT-5.5 Instant: 39.3 (#48)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
LMArena Vision13121250
Blueprint-Bench 238.6%—
Furniture Assembly31.7%—
LMArena Document—1403

Multilingual Gemini 3.8 Flash leads

Gemini 3.8 Flash: 57.9 (#5), GPT-5.5 Instant: 53.0 (#76)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
LMArena Non-English14861417
LMArena Chinese15471457
LMArena French15021428
LMArena German14701410
LMArena Japanese15051408
LMArena Korean14791393
LMArena Russian15071430
LMArena Spanish14921430

Instruction Following Gemini 3.8 Flash leads

Gemini 3.8 Flash: 78.2 (#11), GPT-5.5 Instant: 74.4 (#94)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
LMArena Instruction Following14891407

Long Context Gemini 3.8 Flash leads

Gemini 3.8 Flash: 46.2 (#23), GPT-5.5 Instant: 43.4 (#92)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
LMArena Longer Query15061422

Writing & Preference Gemini 3.8 Flash leads

Gemini 3.8 Flash: 72.1 (#16), GPT-5.5 Instant: 62.0 (#81)

BenchmarkGemini 3.8 FlashGPT-5.5 Instant
LMArena Text14941419
LMArena Creative Writing14851420
LMArena Multi-Turn15031434
EQ-Bench Creative Writing1748—

Frequently asked questions

Is Gemini 3.8 Flash better than GPT-5.5 Instant?

Gemini 3.8 Flash is the stronger model overall, scoring 59.5 to 42.5 on the Noometry Index.

Is Gemini 3.8 Flash or GPT-5.5 Instant better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 56.4 versus 43.7 in the Noometry coding category.

How many benchmarks do Gemini 3.8 Flash and GPT-5.5 Instant share?

26 benchmarks have published results for both models. Gemini 3.8 Flash has 46 scored results on Noometry and GPT-5.5 Instant has 27.

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