Model comparison

Gemini 2.5 Flash-Lite vs GPT-5.3 Chat

GPT-5.3 Chat is the stronger model overall, scoring 42.1 to 36.4 on the Noometry Index. Gemini 2.5 Flash-Lite costs 27× less per token, which makes it the better buy when GPT-5.3 Chat's lead doesn't matter for your workload.

Last verified October 10, 2026. 17 shared benchmarks.

Gemini 2.5 Flash-Lite

Google

36.4

Rank #208 Confirmed

GPT-5.3 Chat OpenAI

42.1

Rank #109 Confirmed

Summary

They share 17 benchmarks with published results for both. Gemini 2.5 Flash-Lite scores higher in 1 category and GPT-5.3 Chat in 7 categories; 7 gaps are clear of the uncertainty.
The widest gap is in long context, where GPT-5.3 Chat leads 42.6 to 33.3.
Gemini 2.5 Flash-Lite is cheaper at $0.10 / $0.40 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
Gemini 2.5 Flash-Lite accepts more context: 1.05M tokens versus 128K.

Side by side

Gemini 2.5 Flash-Lite and GPT-5.3 Chat specifications
	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
Provider	Google	OpenAI
Noometry Index	36.4	42.1
Released	2025-06-17	2026-03-03
Weights	Proprietary	Proprietary
Context window	1.05M	128K
Max output	66K	16K
Input $ / M tokens	$0.10	$1.75
Output $ / M tokens	$0.40	$14
Results tracked	33	18

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Category by category

Coding GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 38.0 (#167), GPT-5.3 Chat: 40.8 (#124)

Coding benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Coding	1373	1408
WeirdML	35.2%	—
ALE-Bench	325.9	—

Agentic & Tool Use Not comparable

Gemini 2.5 Flash-Lite: 27.8 (#89), GPT-5.3 Chat: —

Agentic & Tool Use benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
Berkeley Function Calling Leaderboard	36.9%	—

Reasoning GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 21.5 (#196), GPT-5.3 Chat: 27.3 (#105)

Reasoning benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Hard Prompts	1377	1399
Kagi LLM Benchmark	40.5%	—
DTBench	62.8%	—
LMCA	18.1%	—
Epoch Capabilities Index	133.93	—

Math Too close to call

Gemini 2.5 Flash-Lite: 35.5 (#144), GPT-5.3 Chat: 35.4 (#146)

Math benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Math	1373	1389
Omni-MATH	48%	—

Knowledge GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 32.1 (#206), GPT-5.3 Chat: 38.2 (#137)

Knowledge benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Expert	1373	1397
MMLU-Pro	53.7%	—
Vectara Hallucination Rate	3.3%	—
GPQA (HELM)	30.9%	—

Multimodal Not comparable

Gemini 2.5 Flash-Lite: 28.6 (#109), GPT-5.3 Chat: —

Multimodal benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Vision	1198	—
VPCT	30%	—

Multilingual GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 49.5 (#129), GPT-5.3 Chat: 50.5 (#119)

Multilingual benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Non-English	1369	1383
LMArena Chinese	1404	1433
LMArena French	1388	1398
LMArena German	1390	1384
LMArena Japanese	1359	1351
LMArena Korean	1358	1347
LMArena Russian	1373	1400
LMArena Spanish	1396	1371

Instruction Following GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 70.2 (#163), GPT-5.3 Chat: 73.0 (#124)

Instruction Following benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Instruction Following	1366	1378
IFEval	81%	—

Long Context GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 33.3 (#257), GPT-5.3 Chat: 42.6 (#115)

Long Context benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Longer Query	1373	1396
Fiction.LiveBench	47.2%	—

Writing & Preference GPT-5.3 Chat leads

Gemini 2.5 Flash-Lite: 57.0 (#130), GPT-5.3 Chat: 63.3 (#65)

Writing & Preference benchmarks
Benchmark	Gemini 2.5 Flash-Lite	GPT-5.3 Chat
LMArena Text	1379	1389
LMArena Creative Writing	1366	1356
LMArena Multi-Turn	1367	1413
EQ-Bench Creative Writing	—	1690
WildBench	81.8%	—

Frequently asked questions

Is Gemini 2.5 Flash-Lite better than GPT-5.3 Chat?

Which is cheaper, Gemini 2.5 Flash-Lite or GPT-5.3 Chat?

Gemini 2.5 Flash-Lite is cheaper. It lists at $0.10 per million input tokens and $0.40 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

Is Gemini 2.5 Flash-Lite or GPT-5.3 Chat better for coding?

GPT-5.3 Chat scores higher on coding benchmarks: 40.8 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 128K.

How many benchmarks do Gemini 2.5 Flash-Lite and GPT-5.3 Chat share?

17 benchmarks have published results for both models. Gemini 2.5 Flash-Lite has 33 scored results on Noometry and GPT-5.3 Chat has 18.