Model comparison

Gemini 3.8 Flash vs o3

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 47.5 on the Noometry Index.

Last verified . 34 shared benchmarks.

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

o3 OpenAI

47.5

Rank #61 Confirmed

Summary

  • They share 34 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 8 categories and o3 in 2 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 32.0.
  • The biggest single-benchmark swing is ARC-AGI-2: 89.2% for Gemini 3.8 Flash and 6.5% for o3.
  • Gemini 3.8 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $2 / $8 for o3.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 200K.

Side by side

Gemini 3.8 Flash and o3 specifications
Gemini 3.8 Flasho3
ProviderGoogleOpenAI
Noometry Index61.847.5
Released2026-09-022025-04-16
WeightsProprietaryProprietary
Context window1.05M200K
Max output66K100K
Input $ / M tokens$0.75$2
Output $ / M tokens$3.75$8
Results tracked5063

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Category by category

Coding Gemini 3.8 Flash leads

Gemini 3.8 Flash: 59.2 (#15), o3: 46.8 (#64)

Coding benchmarks
BenchmarkGemini 3.8 Flasho3
WeirdML84.8%52.4%
LMArena Coding15101408
ALE-Bench1,270933.55
SWE-bench Verified—62.3%
DeepSWE73.8%—
FrontierCode41.2%—
SWE-bench Verified (bash only)—58.4%
Aider Polyglot—81.3%
CursorBench39.6%—
LMArena WebDev1584—
FrontierSWE19.6%—
SciCode56.6%—
GSO—8.8%
CadEval—74%

Agentic & Tool Use Gemini 3.8 Flash leads

Gemini 3.8 Flash: 41.8 (#21), o3: 34.5 (#44)

Agentic & Tool Use benchmarks
BenchmarkGemini 3.8 Flasho3
APEX-Agents64.3%—
Berkeley Function Calling Leaderboard—63%
GDPval—30.8%
Remote Labor Index5.8%—
DeepResearch Bench—45.2%
OSWorld—23%
GDP.pdf23.4%—
LMArena Search—1144
METR Time Horizons—65.4%
Vending-Bench 25,094—

Reasoning Gemini 3.8 Flash leads

Gemini 3.8 Flash: 76.9 (#5), o3: 32.0 (#78)

Reasoning benchmarks
BenchmarkGemini 3.8 Flasho3
ARC-AGI-289.2%6.5%
ARC-AGI-198.5%60.8%
CritPt18.3%1.4%
Chess Puzzles61%38%
LMArena Hard Prompts15081402
Mystery Game Puzzles47%29%
DTBench95.7%84.8%
LMCA52.9%39.7%
Epoch Capabilities Index156.71146.86
SimpleBench—53.1%
Kagi LLM Benchmark—67.6%
NYT Connections (extended)97.4%—
EnigmaEval—13.1%
Surface Evolver Bench76.9%—
ForecastBench—62.5

Math Gemini 3.8 Flash leads

Gemini 3.8 Flash: 65.3 (#28), o3: 50.2 (#58)

Math benchmarks
BenchmarkGemini 3.8 Flasho3
FrontierMath (Tiers 1-3)68.4%33.3%
OTIS Mock AIME 2024-202598.9%84.4%
LMArena Math15281426
FrontierMath Tier 422%—
ProofBench48%—
Omni-MATH—71.4%
MATH Level 5—97.8%
FrontierMath (Feb 2025 set)—18.7%
FrontierMath Tier 4 (v1)—2.1%

Knowledge Gemini 3.8 Flash leads

Gemini 3.8 Flash: 74.8 (#2), o3: 54.6 (#52)

Knowledge benchmarks
BenchmarkGemini 3.8 Flasho3
GPQA Diamond95.4%81.8%
Humanity's Last Exam44.5%20.3%
SimpleQA Verified69.7%49.4%
LMArena Expert15241402
MMLU-Pro—85.9%
Confabulations—14.4%
GPQA (HELM)—75.3%

Multimodal Too close to call

Gemini 3.8 Flash: 40.7 (#45), o3: 41.4 (#36)

Multimodal benchmarks
BenchmarkGemini 3.8 Flasho3
LMArena Vision13141214
GeoBench—74%
VPCT—52%
Blueprint-Bench 238.6%—
Furniture Assembly31.7%—

Multilingual Gemini 3.8 Flash leads

Gemini 3.8 Flash: 58.0 (#5), o3: 51.7 (#105)

Multilingual benchmarks
BenchmarkGemini 3.8 Flasho3
LMArena Non-English14911401
LMArena Chinese15541437
LMArena French14981430
LMArena German14931420
LMArena Japanese15021403
LMArena Korean14591370
LMArena Russian15151406
LMArena Spanish14851395

Instruction Following Gemini 3.8 Flash leads

Gemini 3.8 Flash: 78.0 (#13), o3: 72.8 (#127)

Instruction Following benchmarks
BenchmarkGemini 3.8 Flasho3
LMArena Instruction Following14901368
IFEval—86.9%

Long Context o3 leads

Gemini 3.8 Flash: 46.3 (#24), o3: 53.3 (#6)

Long Context benchmarks
BenchmarkGemini 3.8 Flasho3
LMArena Longer Query15081372
Fiction.LiveBench—88.9%
CL-bench—17.8%

Writing & Preference Gemini 3.8 Flash leads

Gemini 3.8 Flash: 72.2 (#15), o3: 63.5 (#64)

Writing & Preference benchmarks
BenchmarkGemini 3.8 Flasho3
LMArena Text14991410
LMArena Creative Writing14921359
EQ-Bench Creative Writing17481676
LMArena Multi-Turn15011405
Short-Story Creative Writing—83.9%
WildBench—86.1%

Frequently asked questions

Is Gemini 3.8 Flash better than o3?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 47.5 on the Noometry Index.

Which is cheaper, Gemini 3.8 Flash or o3?

Gemini 3.8 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; o3 lists at $2 and $8.

Is Gemini 3.8 Flash or o3 better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 46.8 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 200K.

How many benchmarks do Gemini 3.8 Flash and o3 share?

34 benchmarks have published results for both models. Gemini 3.8 Flash has 50 scored results on Noometry and o3 has 63.

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