Model comparison

Gemini 1.5 Flash 8B vs Gemini 3.1 Pro Preview

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 29.9 on the Noometry Index.

Last verified . 21 shared benchmarks.

Gemini 1.5 Flash 8B Google

29.9

Rank #301 Confirmed

Gemini 3.1 Pro Preview Google

56.7

Rank #23 Confirmed

Summary

  • They share 21 benchmarks with published results for both. Gemini 1.5 Flash 8B scores higher in 0 categories and Gemini 3.1 Pro Preview in 9 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Gemini 3.1 Pro Preview leads 71.8 to 16.0.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 4.6% for Gemini 1.5 Flash 8B and 95.6% for Gemini 3.1 Pro Preview.

Side by side

Gemini 1.5 Flash 8B and Gemini 3.1 Pro Preview specifications
Gemini 1.5 Flash 8BGemini 3.1 Pro Preview
ProviderGoogleGoogle
Noometry Index29.956.7
Released2024-10-032026-02-19
WeightsProprietaryProprietary
Context window—1.05M
Max output—66K
Input $ / M tokens—$2
Output $ / M tokens—$12
Results tracked2171

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Category by category

Coding Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 35.5 (#225), Gemini 3.1 Pro Preview: 42.5 (#99)

Coding benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Coding12181484
SWE-bench Verified—75.6%
DeepSWE—11.7%
LMArena WebDev—1447
SciCode—58.9%
GSO—22.6%
WeirdML—72.1%
MirrorCode—8.9%
ALE-Bench—1,161
AlgoTune—2.02

Agentic & Tool Use Not comparable

Gemini 1.5 Flash 8B: —, Gemini 3.1 Pro Preview: 37.7 (#34)

Agentic & Tool Use benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
Terminal-Bench—80.2%
APEX-Agents—35.3%
τ²-bench Banking—26%
DeepResearch Bench—47.8%
PostTrainBench—22%
BALROG—57%
ExploitBench—26.1%
GBAEval—0.8%
GDP.pdf—17%
LMArena Search—1211
METR Time Horizons—77%
Vending-Bench 2—3,774

Reasoning Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 20.0 (#244), Gemini 3.1 Pro Preview: 71.7 (#12)

Reasoning benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Hard Prompts12091485
DTBench50%97.1%
ARC-AGI-2—77.1%
SimpleBench—79.6%
NYT Connections (extended)—97.4%
ARC-AGI-1—98%
CritPt—17.7%
Chess Puzzles—55%
EnigmaEval—36.8%
Thematic Generalization—79.4%
EBR-Bench—14.3%
Mystery Game Puzzles—34%
LMCA—53.8%
Epoch Capabilities Index—154.77
ForecastBench—59

Math Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 14.2 (#302), Gemini 3.1 Pro Preview: 62.1 (#34)

Math benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
OTIS Mock AIME 2024-20254.6%95.6%
LMArena Math12071485
FrontierMath (Tiers 1-3)—59.6%
FrontierMath Tier 4—26.8%
MathArena Final-Answer Competitions—86.5%
ProofBench—26%
FrontierMath (Feb 2025 set)—36.9%
FrontierMath Tier 4 (v1)—16.7%

Knowledge Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 16.0 (#289), Gemini 3.1 Pro Preview: 71.8 (#3)

Knowledge benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
GPQA Diamond33%94.4%
LMArena Expert11851485
Humanity's Last Exam—46.4%
SimpleQA Verified—73.5%
Vectara Hallucination Rate—10.4%

Multimodal Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 28.2 (#115), Gemini 3.1 Pro Preview: 37.9 (#69)

Multimodal benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Vision10441296
Blueprint-Bench 2—26.5%
Furniture Assembly—26.7%
LMArena Document—1444

Multilingual Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 38.5 (#229), Gemini 3.1 Pro Preview: 57.0 (#12)

Multilingual benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Non-English12151477
LMArena Chinese12311529
LMArena French12341487
LMArena German12061491
LMArena Japanese11501493
LMArena Korean11401455
LMArena Russian12361498
LMArena Spanish12121479

Instruction Following Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 62.8 (#236), Gemini 3.1 Pro Preview: 77.0 (#32)

Instruction Following benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Instruction Following11991466

Long Context Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 37.0 (#225), Gemini 3.1 Pro Preview: 47.4 (#18)

Long Context benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Longer Query12191483
CL-bench—20.8%
CL-bench Life—16.9%

Writing & Preference Gemini 3.1 Pro Preview leads

Gemini 1.5 Flash 8B: 42.8 (#232), Gemini 3.1 Pro Preview: 66.1 (#37)

Writing & Preference benchmarks
BenchmarkGemini 1.5 Flash 8BGemini 3.1 Pro Preview
LMArena Text12261481
LMArena Creative Writing12181482
LMArena Multi-Turn11851488
EQ-Bench Creative Writing—1491
EQ-Bench 4—1142

Frequently asked questions

Is Gemini 1.5 Flash 8B better than Gemini 3.1 Pro Preview?

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 29.9 on the Noometry Index.

Is Gemini 1.5 Flash 8B or Gemini 3.1 Pro Preview better for coding?

Gemini 3.1 Pro Preview scores higher on coding benchmarks: 42.5 versus 35.5 in the Noometry coding category.

How many benchmarks do Gemini 1.5 Flash 8B and Gemini 3.1 Pro Preview share?

21 benchmarks have published results for both models. Gemini 1.5 Flash 8B has 21 scored results on Noometry and Gemini 3.1 Pro Preview has 71.

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