Model comparison

Gemini 3.8 Flash vs GPT-5

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 50.9 on the Noometry Index.

Last verified . 39 shared benchmarks.

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

GPT-5 OpenAI

50.9

Rank #45 Confirmed

Summary

  • They share 39 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 8 categories and GPT-5 in 2 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 38.3.
  • The biggest single-benchmark swing is ARC-AGI-2: 89.2% for Gemini 3.8 Flash and 9.9% for GPT-5.
  • Gemini 3.8 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $1.25 / $10 for GPT-5.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 400K.

Side by side

Gemini 3.8 Flash and GPT-5 specifications
Gemini 3.8 FlashGPT-5
ProviderGoogleOpenAI
Noometry Index61.850.9
Released2026-09-022025-08-07
WeightsProprietaryProprietary
Context window1.05M400K
Max output66K128K
Input $ / M tokens$0.75$1.25
Output $ / M tokens$3.75$10
Results tracked5069

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Category by category

Coding Gemini 3.8 Flash leads

Gemini 3.8 Flash: 59.2 (#15), GPT-5: 50.3 (#47)

Coding benchmarks
BenchmarkGemini 3.8 FlashGPT-5
LMArena WebDev15841418
SciCode56.6%42.9%
WeirdML84.8%60.7%
LMArena Coding15101436
ALE-Bench1,2701,162
SWE-bench Verified—73.6%
DeepSWE73.8%—
FrontierCode41.2%—
SWE-bench Verified (bash only)—65%
Aider Polyglot—88%
CursorBench39.6%—
FrontierSWE19.6%—
GSO—6.9%
AlgoTune—1.67

Agentic & Tool Use Gemini 3.8 Flash leads

Gemini 3.8 Flash: 41.8 (#21), GPT-5: 33.1 (#56)

Agentic & Tool Use benchmarks
BenchmarkGemini 3.8 FlashGPT-5
Remote Labor Index5.8%1.7%
Terminal-Bench—49.6%
APEX-Agents64.3%—
GDPval—34.8%
DeepResearch Bench—49.6%
BALROG—32.8%
GDP.pdf23.4%—
LMArena Search—1133
METR Time Horizons—69.6%
Vending-Bench 25,094—

Reasoning Gemini 3.8 Flash leads

Gemini 3.8 Flash: 76.9 (#5), GPT-5: 38.3 (#64)

Reasoning benchmarks
BenchmarkGemini 3.8 FlashGPT-5
ARC-AGI-289.2%9.9%
ARC-AGI-198.5%65.7%
CritPt18.3%12.6%
Chess Puzzles61%37%
LMArena Hard Prompts15081416
Mystery Game Puzzles47%23%
DTBench95.7%90.7%
LMCA52.9%40%
Epoch Capabilities Index156.71150
SimpleBench—56.7%
Kagi LLM Benchmark—72.7%
NYT Connections (extended)97.4%—
EnigmaEval—10.5%
EBR-Bench—12.7%
Surface Evolver Bench76.9%—
ForecastBench—61.4

Math Gemini 3.8 Flash leads

Gemini 3.8 Flash: 65.3 (#28), GPT-5: 55.0 (#44)

Math benchmarks
BenchmarkGemini 3.8 FlashGPT-5
FrontierMath (Tiers 1-3)68.4%55.4%
FrontierMath Tier 422%22%
OTIS Mock AIME 2024-202598.9%91.4%
ProofBench48%18%
LMArena Math15281407
Omni-MATH—64.7%
MATH Level 5—98.1%
FrontierMath (Feb 2025 set)—32.4%
FrontierMath Tier 4 (v1)—12.5%

Knowledge Gemini 3.8 Flash leads

Gemini 3.8 Flash: 74.8 (#2), GPT-5: 56.6 (#43)

Knowledge benchmarks
BenchmarkGemini 3.8 FlashGPT-5
GPQA Diamond95.4%86.2%
Humanity's Last Exam44.5%25.3%
SimpleQA Verified69.7%50.1%
LMArena Expert15241419
MMLU-Pro—86.3%
Confabulations—10.3%
Vectara Hallucination Rate—14.7%
GPQA (HELM)—79.2%

Multimodal GPT-5 leads

Gemini 3.8 Flash: 40.7 (#45), GPT-5: 46.8 (#13)

Multimodal benchmarks
BenchmarkGemini 3.8 FlashGPT-5
LMArena Vision13141232
GeoBench—81%
VPCT—66%
Blueprint-Bench 238.6%—
Furniture Assembly31.7%—

Multilingual Gemini 3.8 Flash leads

Gemini 3.8 Flash: 58.0 (#5), GPT-5: 51.4 (#110)

Multilingual benchmarks
BenchmarkGemini 3.8 FlashGPT-5
LMArena Non-English14911397
LMArena Chinese15541422
LMArena French14981410
LMArena German14931416
LMArena Japanese15021409
LMArena Korean14591360
LMArena Russian15151406
LMArena Spanish14851399

Instruction Following Gemini 3.8 Flash leads

Gemini 3.8 Flash: 78.0 (#13), GPT-5: 73.8 (#113)

Instruction Following benchmarks
BenchmarkGemini 3.8 FlashGPT-5
LMArena Instruction Following14901388
IFEval—87.5%

Long Context GPT-5 leads

Gemini 3.8 Flash: 46.3 (#24), GPT-5: 69.5 (#2)

Long Context benchmarks
BenchmarkGemini 3.8 FlashGPT-5
LMArena Longer Query15081399
Fiction.LiveBench—97.2%

Writing & Preference Gemini 3.8 Flash leads

Gemini 3.8 Flash: 72.2 (#15), GPT-5: 63.4 (#65)

Writing & Preference benchmarks
BenchmarkGemini 3.8 FlashGPT-5
LMArena Text14991406
LMArena Creative Writing14921365
EQ-Bench Creative Writing17481627
LMArena Multi-Turn15011426
Short-Story Creative Writing—86%
WildBench—85.7%

Frequently asked questions

Is Gemini 3.8 Flash better than GPT-5?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 50.9 on the Noometry Index.

Which is cheaper, Gemini 3.8 Flash or GPT-5?

Gemini 3.8 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; GPT-5 lists at $1.25 and $10.

Is Gemini 3.8 Flash or GPT-5 better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 50.3 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 400K.

How many benchmarks do Gemini 3.8 Flash and GPT-5 share?

39 benchmarks have published results for both models. Gemini 3.8 Flash has 50 scored results on Noometry and GPT-5 has 69.

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