Noometry

Model comparison

Gemini 2.5 Pro vs Gemini 3.1 Flash Lite

Gemini 2.5 Pro is the stronger model overall, scoring 44.9 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 6.1× less per token, which makes it the better buy when Gemini 2.5 Pro's lead doesn't matter for your workload.

Last verified . 36 shared benchmarks.

Gemini 2.5 Pro Google

44.9

Rank #67 Confirmed

Gemini 3.1 Flash Lite Google

40.4

Rank #141 Confirmed

Summary

  • They share 36 benchmarks with published results for both. Gemini 2.5 Pro scores higher in 8 categories and Gemini 3.1 Flash Lite in 2 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in long context, where Gemini 2.5 Pro leads 59.7 to 42.5.
  • The biggest single-benchmark swing is Humanity's Last Exam: 21.6% for Gemini 2.5 Pro and 8.6% for Gemini 3.1 Flash Lite.
  • Gemini 3.1 Flash Lite is cheaper at $0.25 / $1.50 per million input/output tokens, against $1.25 / $10 for Gemini 2.5 Pro.

Side by side

Gemini 2.5 ProGemini 3.1 Flash Lite
ProviderGoogleGoogle
Noometry Index44.940.4
Released2025-03-252026-03-03
WeightsProprietaryProprietary
Context window1.05M1.05M
Max output66K66K
Input $ / M tokens$1.25$0.25
Output $ / M tokens$10$1.50
Results tracked7838

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Category by category

Coding Gemini 2.5 Pro leads

Gemini 2.5 Pro: 42.8 (#86), Gemini 3.1 Flash Lite: 37.5 (#179)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
LMArena WebDev12271256
SciCode42.8%41.9%
WeirdML54%52.2%
LMArena Coding14521400
ALE-Bench785.52797.73
SWE-bench Verified57.6%—
SWE-bench Verified (bash only)53.6%—
Aider Polyglot83.1%—
GSO3.9%—
LiveBench Coding85.9%—
CadEval64%—
AlgoTune1.51—

Agentic & Tool Use Too close to call

Gemini 2.5 Pro: 29.1 (#81), Gemini 3.1 Flash Lite: 29.9 (#72)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
DeepResearch Bench42.8%37.3%
Terminal-Bench32.6%—
GDPval23.3%—
Remote Labor Index0.8%—
TheAgentCompany30.3%—
τ²-bench Banking13.7%—
BALROG43.3%—
LMArena Search1142—
METR Time Horizons55.4%—
Vending-Bench 2573.64—

Reasoning Gemini 2.5 Pro leads

Gemini 2.5 Pro: 28.8 (#85), Gemini 3.1 Flash Lite: 22.3 (#181)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
Kagi LLM Benchmark70.3%67.2%
CritPt2%1.1%
Chess Puzzles20%25%
EnigmaEval5.6%3%
LMArena Hard Prompts14551407
DTBench82.4%76.8%
LMCA34.8%35%
Epoch Capabilities Index145.32144.45
ForecastBench61.354.4
ARC-AGI-24.9%—
SimpleBench62.4%—
NYT Connections (extended)—8.2%
ARC-AGI-141%—
Thematic Generalization—63.3%
LiveBench Reasoning89.8%—
LiveBench Data Analysis79.9%—
LiveBench82.3%—

Math Gemini 3.1 Flash Lite leads

Gemini 2.5 Pro: 31.9 (#191), Gemini 3.1 Flash Lite: 39.5 (#82)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
FrontierMath (Tiers 1-3)24.6%27.7%
OTIS Mock AIME 2024-202584.7%80%
LMArena Math14501427
FrontierMath Tier 40%—
Omni-MATH41.6%—
LiveBench Math90.2%—
MATH Level 595.9%—
FrontierMath (Feb 2025 set)14.1%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Gemini 2.5 Pro leads

Gemini 2.5 Pro: 55.8 (#41), Gemini 3.1 Flash Lite: 41.7 (#95)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
GPQA Diamond85.3%81.8%
Humanity's Last Exam21.6%8.6%
Vectara Hallucination Rate7%8.2%
LMArena Expert14521397
MMLU-Pro86.3%—
Confabulations10.6%—
GPQA (HELM)74.9%—

Multimodal Gemini 2.5 Pro leads

Gemini 2.5 Pro: 44.5 (#16), Gemini 3.1 Flash Lite: 38.7 (#57)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
LMArena Vision12631240
GeoBench86%—
VPCT48%—
LMArena Document1421—
SpatialViz-Bench44.7%—

Multilingual Gemini 2.5 Pro leads

Gemini 2.5 Pro: 55.5 (#30), Gemini 3.1 Flash Lite: 52.5 (#82)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
LMArena Non-English14521410
LMArena Chinese15071461
LMArena French14731423
LMArena German14871429
LMArena Japanese14621411
LMArena Korean14351393
LMArena Russian14601420
LMArena Spanish14731420

Instruction Following Gemini 2.5 Pro leads

Gemini 2.5 Pro: 75.2 (#71), Gemini 3.1 Flash Lite: 72.9 (#126)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
LMArena Instruction Following14361376
LiveBench Instruction Following80.6%—
IFEval84%—

Long Context Gemini 2.5 Pro leads

Gemini 2.5 Pro: 59.7 (#5), Gemini 3.1 Flash Lite: 42.5 (#117)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
LMArena Longer Query14491394
Fiction.LiveBench91.7%—

Writing & Preference Gemini 2.5 Pro leads

Gemini 2.5 Pro: 63.9 (#60), Gemini 3.1 Flash Lite: 61.0 (#90)

BenchmarkGemini 2.5 ProGemini 3.1 Flash Lite
LMArena Text14581416
LMArena Creative Writing14531401
LMArena Multi-Turn14531417
Short-Story Creative Writing83.8%—
EQ-Bench Creative Writing1421—
WildBench85.7%—
LiveBench Language67.8%—

Frequently asked questions

Is Gemini 2.5 Pro better than Gemini 3.1 Flash Lite?

Gemini 2.5 Pro is the stronger model overall, scoring 44.9 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 6.1× less per token, which makes it the better buy when Gemini 2.5 Pro's lead doesn't matter for your workload.

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

Gemini 3.1 Flash Lite is cheaper. It lists at $0.25 per million input tokens and $1.50 per million output tokens; Gemini 2.5 Pro lists at $1.25 and $10.

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

Gemini 2.5 Pro scores higher on coding benchmarks: 42.8 versus 37.5 in the Noometry coding category.

Which has the bigger context window?

Both accept 1.05M tokens.

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

36 benchmarks have published results for both models. Gemini 2.5 Pro has 78 scored results on Noometry and Gemini 3.1 Flash Lite has 38.

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