Model comparison

Gemini 2.5 Flash-Lite vs GPT-5.1

GPT-5.1 is the stronger model overall, scoring 48.8 to 36.4 on the Noometry Index. Gemini 2.5 Flash-Lite costs 20× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 30 shared benchmarks.

Gemini 2.5 Flash-Lite Google

36.4

Rank #208 Confirmed

GPT-5.1 OpenAI

48.8

Rank #47 Confirmed

Summary

  • They share 30 benchmarks with published results for both. Gemini 2.5 Flash-Lite scores higher in 0 categories and GPT-5.1 in 10 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.1 leads 39.9 to 21.5.
  • The biggest single-benchmark swing is VPCT: 30% for Gemini 2.5 Flash-Lite and 58.7% for GPT-5.1.
  • Gemini 2.5 Flash-Lite is cheaper at $0.10 / $0.40 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • Gemini 2.5 Flash-Lite accepts more context: 1.05M tokens versus 400K.

Side by side

Gemini 2.5 Flash-Lite and GPT-5.1 specifications
Gemini 2.5 Flash-LiteGPT-5.1
ProviderGoogleOpenAI
Noometry Index36.448.8
Released2025-06-172025-11-13
WeightsProprietaryProprietary
Context window1.05M400K
Max output66K128K
Input $ / M tokens$0.10$1.25
Output $ / M tokens$0.40$10
Results tracked3363

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Category by category

Coding GPT-5.1 leads

Gemini 2.5 Flash-Lite: 38.0 (#167), GPT-5.1: 46.9 (#59)

Coding benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
WeirdML35.2%60.8%
LMArena Coding13731454
ALE-Bench325.91,192
SWE-bench Verified—68%
SWE-bench Verified (bash only)—66%
LMArena WebDev—1395
SciCode—43.3%
GSO—13.7%
LiveBench Coding—72.5%

Agentic & Tool Use GPT-5.1 leads

Gemini 2.5 Flash-Lite: 27.8 (#89), GPT-5.1: 32.5 (#55)

Agentic & Tool Use benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
Terminal-Bench—47.6%
Berkeley Function Calling Leaderboard36.9%—
DeepResearch Bench—42.8%
LMArena Search—1199
Vending-Bench 2—1,473

Reasoning GPT-5.1 leads

Gemini 2.5 Flash-Lite: 21.5 (#196), GPT-5.1: 39.9 (#50)

Reasoning benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
LMArena Hard Prompts13771457
DTBench62.8%90.1%
LMCA18.1%43.9%
Epoch Capabilities Index133.93149.66
ARC-AGI-2—17.6%
SimpleBench—53.2%
Kagi LLM Benchmark40.5%—
ARC-AGI-1—72.8%
CritPt—4.9%
Chess Puzzles—32%
EnigmaEval—11.2%
LiveBench Reasoning—95.8%
Mystery Game Puzzles—19%
LiveBench Data Analysis—72.1%
ForecastBench—58.1
LiveBench—78.8%

Math GPT-5.1 leads

Gemini 2.5 Flash-Lite: 35.5 (#144), GPT-5.1: 50.3 (#45)

Math benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
Omni-MATH48%46.4%
LMArena Math13731446
OTIS Mock AIME 2024-2025—88.6%
LiveBench Math—94.5%
FrontierMath (Feb 2025 set)—31%
FrontierMath Tier 4 (v1)—12.5%

Knowledge GPT-5.1 leads

Gemini 2.5 Flash-Lite: 32.1 (#206), GPT-5.1: 50.5 (#65)

Knowledge benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
MMLU-Pro53.7%57.9%
Vectara Hallucination Rate3.3%10.9%
GPQA (HELM)30.9%44.2%
LMArena Expert13731470
GPQA Diamond—87.6%
Humanity's Last Exam—23.7%
SimpleQA Verified—48%

Multimodal GPT-5.1 leads

Gemini 2.5 Flash-Lite: 28.6 (#109), GPT-5.1: 44.0 (#17)

Multimodal benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
LMArena Vision11981250
VPCT30%58.7%
LMArena Document—1403

Multilingual GPT-5.1 leads

Gemini 2.5 Flash-Lite: 49.5 (#129), GPT-5.1: 54.0 (#51)

Multilingual benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
LMArena Non-English13691431
LMArena Chinese14041495
LMArena French13881451
LMArena German13901439
LMArena Japanese13591453
LMArena Korean13581401
LMArena Russian13731435
LMArena Spanish13961430

Instruction Following GPT-5.1 leads

Gemini 2.5 Flash-Lite: 70.2 (#163), GPT-5.1: 84.0 (#1)

Instruction Following benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
IFEval81%93.5%
LMArena Instruction Following13661442
LiveBench Instruction Following—93.3%

Long Context GPT-5.1 leads

Gemini 2.5 Flash-Lite: 33.3 (#257), GPT-5.1: 47.6 (#14)

Long Context benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
LMArena Longer Query13731448
Fiction.LiveBench47.2%—
CL-bench—23.7%
CL-bench Life—17.3%

Writing & Preference GPT-5.1 leads

Gemini 2.5 Flash-Lite: 57.0 (#130), GPT-5.1: 64.7 (#53)

Writing & Preference benchmarks
BenchmarkGemini 2.5 Flash-LiteGPT-5.1
LMArena Text13791443
LMArena Creative Writing13661427
WildBench81.8%86.3%
LMArena Multi-Turn13671449
LiveBench Language—80.2%

Frequently asked questions

Is Gemini 2.5 Flash-Lite better than GPT-5.1?

GPT-5.1 is the stronger model overall, scoring 48.8 to 36.4 on the Noometry Index. Gemini 2.5 Flash-Lite costs 20× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Which is cheaper, Gemini 2.5 Flash-Lite or GPT-5.1?

Gemini 2.5 Flash-Lite is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is Gemini 2.5 Flash-Lite or GPT-5.1 better for coding?

GPT-5.1 scores higher on coding benchmarks: 46.9 versus 38.0 in the Noometry coding category.

Which has the bigger context window?

Gemini 2.5 Flash-Lite does, with 1.05M tokens against 400K.

How many benchmarks do Gemini 2.5 Flash-Lite and GPT-5.1 share?

30 benchmarks have published results for both models. Gemini 2.5 Flash-Lite has 33 scored results on Noometry and GPT-5.1 has 63.

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