Noometry

Model comparison

Gemini 2.5 Flash-Lite vs Gemini 3.1 Pro Preview

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 37.0 on the Noometry Index. Gemini 2.5 Flash-Lite costs 26× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

Last verified . 24 shared benchmarks.

Gemini 2.5 Flash-Lite Google

37.0

Rank #211 Confirmed

Gemini 3.1 Pro Preview Google

56.7

Rank #23 Confirmed

Summary

  • They share 24 benchmarks with published results for both. Gemini 2.5 Flash-Lite scores higher in 0 categories and Gemini 3.1 Pro Preview in 10 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.1 Pro Preview leads 71.7 to 22.2.
  • The biggest single-benchmark swing is WeirdML: 35.2% for Gemini 2.5 Flash-Lite and 72.1% for Gemini 3.1 Pro Preview.
  • Gemini 2.5 Flash-Lite is cheaper at $0.10 / $0.40 per million input/output tokens, against $2 / $12 for Gemini 3.1 Pro Preview.

Side by side

Gemini 2.5 Flash-LiteGemini 3.1 Pro Preview
ProviderGoogleGoogle
Noometry Index37.056.7
Released2025-06-172026-02-19
WeightsProprietaryProprietary
Context window1.05M1.05M
Max output66K66K
Input $ / M tokens$0.10$2
Output $ / M tokens$0.40$12
Results tracked3371

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 38.5 (#173), Gemini 3.1 Pro Preview: 42.5 (#99)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
WeirdML35.2%72.1%
LMArena Coding13731484
ALE-Bench325.91,161
SWE-bench Verified—75.6%
DeepSWE—11.7%
LMArena WebDev—1447
SciCode—58.9%
GSO—22.6%
MirrorCode—8.9%
AlgoTune—2.02

Agentic & Tool Use Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 28.0 (#96), Gemini 3.1 Pro Preview: 37.7 (#34)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
Terminal-Bench—80.2%
APEX-Agents—35.3%
Berkeley Function Calling Leaderboard36.9%—
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 2.5 Flash-Lite: 22.2 (#205), Gemini 3.1 Pro Preview: 71.7 (#12)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Hard Prompts13771485
DTBench62.8%97.1%
LMCA18.1%53.8%
Epoch Capabilities Index133.94154.77
ARC-AGI-2—77.1%
SimpleBench—79.6%
Kagi LLM Benchmark40.5%—
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%
ForecastBench—59

Math Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 38.0 (#144), Gemini 3.1 Pro Preview: 62.1 (#34)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Math13731485
FrontierMath (Tiers 1-3)—59.6%
FrontierMath Tier 4—26.8%
MathArena Final-Answer Competitions—86.5%
OTIS Mock AIME 2024-2025—95.6%
ProofBench—26%
Omni-MATH48%—
FrontierMath (Feb 2025 set)—36.9%
FrontierMath Tier 4 (v1)—16.7%

Knowledge Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 32.5 (#210), Gemini 3.1 Pro Preview: 71.8 (#3)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
Vectara Hallucination Rate3.3%10.4%
LMArena Expert13731485
GPQA Diamond—94.4%
Humanity's Last Exam—46.4%
SimpleQA Verified—73.5%
MMLU-Pro53.7%—
GPQA (HELM)30.9%—

Multimodal Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 29.1 (#114), Gemini 3.1 Pro Preview: 37.9 (#69)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Vision11981296
VPCT30%—
Blueprint-Bench 2—26.5%
Furniture Assembly—26.7%
LMArena Document—1444

Multilingual Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 49.3 (#134), Gemini 3.1 Pro Preview: 57.0 (#12)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Non-English13691477
LMArena Chinese14041529
LMArena French13881487
LMArena German13891491
LMArena Japanese13591493
LMArena Korean13601455
LMArena Russian13731498
LMArena Spanish13961479

Instruction Following Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 70.0 (#168), Gemini 3.1 Pro Preview: 77.0 (#32)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Instruction Following13671466
IFEval81%—

Long Context Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 33.3 (#262), Gemini 3.1 Pro Preview: 47.4 (#18)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Longer Query13731483
Fiction.LiveBench47.2%—
CL-bench—20.8%
CL-bench Life—16.9%

Writing & Preference Gemini 3.1 Pro Preview leads

Gemini 2.5 Flash-Lite: 56.8 (#135), Gemini 3.1 Pro Preview: 66.1 (#37)

BenchmarkGemini 2.5 Flash-LiteGemini 3.1 Pro Preview
LMArena Text13791481
LMArena Creative Writing13671482
LMArena Multi-Turn13661488
EQ-Bench Creative Writing—1491
WildBench81.8%—
EQ-Bench 4—1142

Frequently asked questions

Is Gemini 2.5 Flash-Lite better than Gemini 3.1 Pro Preview?

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 37.0 on the Noometry Index. Gemini 2.5 Flash-Lite costs 26× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

Which is cheaper, Gemini 2.5 Flash-Lite or Gemini 3.1 Pro Preview?

Gemini 2.5 Flash-Lite is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; Gemini 3.1 Pro Preview lists at $2 and $12.

Is Gemini 2.5 Flash-Lite or Gemini 3.1 Pro Preview better for coding?

Gemini 3.1 Pro Preview scores higher on coding benchmarks: 42.5 versus 38.5 in the Noometry coding category.

Which has the bigger context window?

Both accept 1.05M tokens.

How many benchmarks do Gemini 2.5 Flash-Lite and Gemini 3.1 Pro Preview share?

24 benchmarks have published results for both models. Gemini 2.5 Flash-Lite has 33 scored results on Noometry and Gemini 3.1 Pro Preview has 71.

Related comparisons

Go deeper