Head to head · tested 27 Oct 2026

Gemini 3.5 Flash Lite vs GPT-6 Luna: accuracy, speed and price

Similar accuracy; GPT-6 Luna costs less per question.

GoogleGemini 3.5 Flash Lite75.0% score · #15$0.0034 per question409 tok/sOpenAIGPT-6 Luna72.5% score · #21$0.00025 per question137 tok/s

Verdict

Built from the measurements below

  • Accuracy is too close to call: Gemini 3.5 Flash Lite scored 75.0% and GPT-6 Luna 72.5% on the same 80 questions, a gap within what chance alone could produce.
  • GPT-6 Luna is 14× cheaper per question as billed ($0.00025 vs $0.0034), reasoning tokens included.
  • Gemini 3.5 Flash Lite generates text 3.0× faster: 409 tokens per second against 137.
  • Gemini 3.5 Flash Lite starts answering sooner: 1.1 s to the first token, against 1.2 s for GPT-6 Luna.

Which should you choose?

Choose Gemini 3.5 Flash Lite for faster streaming and a quicker first token. Choose GPT-6 Luna for the lower cost per correct answer ($0.00034 against $0.0045) and shorter outputs (about 431 tokens per question against 1,311).

Accuracy gap +2.5 points (z = 0.36). A winner is called only when z is at least 1.96, the usual 95% threshold. Speed, latency and price need a 10% margin.

Head to head

Same questions, same prompt, same API

MeasureGemini 3.5 Flash LiteGPT-6 LunaEdge
Verification scoreHigher is better75.0%72.5%Too close to call
Cost per questionLower is better$0.0034$0.00025GPT-6 Luna
Output speedHigher is better409137Gemini 3.5 Flash Lite
Time to first tokenLower is better1.1 s1.2 sGemini 3.5 Flash Lite
End-to-end response timeLower is better2.8 s4.3 sGemini 3.5 Flash Lite
Tokens per questionLower is better1,311431GPT-6 Luna
Context windowHigher is better1M1.1MSimilar

Side by side

Bars are scaled to the larger of the two values. The winner on each measure is marked in bold.

Every measure

Gemini 3.5 Flash Lite first, GPT-6 Luna second

Verification scorehigher is better
Gemini 3.5 Flash Lite75.0%
GPT-6 Luna72.5%
Cost per questionlower is better
Gemini 3.5 Flash Lite$0.0034
GPT-6 Luna$0.00025
Output speedhigher is better
Gemini 3.5 Flash Lite409
GPT-6 Luna137
Time to first tokenlower is better
Gemini 3.5 Flash Lite1.1 s
GPT-6 Luna1.2 s
End-to-end response timelower is better
Gemini 3.5 Flash Lite2.8 s
GPT-6 Luna4.3 s
Tokens per questionlower is better
Gemini 3.5 Flash Lite1,311
GPT-6 Luna431
Context windowhigher is better
Gemini 3.5 Flash Lite1M
GPT-6 Luna1.1M

Score vs. cost per question

Both models in color, every other model in grey

Most attractive quadrant0255075100$0.00001$0.0001$0.001$0.01$0.10Cost per question (USD, log) →Verification score (%) →Qwen3.8 2.4T A95BCommand AReka Flash 3Gemma 4 26B A4BGemma 4 31BQwen3.5 397B A17BHermes 4 405BMuse WonderGrok 4.7o3gpt-oss-20bMinistral 3 3B 2512Nova Micro 1.0Phi 4Granite 4.2 8BHy3GLM 5.3 FlashSolar Pro 4Trinity Large ThinkingMiniMax M3Mistral Large 4Claude Opus 5.5GPT-6.1 SolGemini 4 ArgonGPT-5.4GPT-6 Lunagpt-oss-120bLlama 4 Maverick

Specifications and pricing

From OpenRouter's catalogue, plus the leaderboard's test dates

SpecificationGemini 3.5 Flash LiteGPT-6 Luna
CreatorGoogleOpenAI
Released21 Jul 202622 Sept 2026
Weights——
ReasoningYesYes
Inputtext, image, video, file, audiofile, image, text
Outputtexttext
Context window1M tokens1.1M tokens
Knowledge cutoff——
List price in / out per 1M$0.3 / $2.5$0.1 / $0.5
Blended price per 1M (3:1)$0.85$0.20
Cheapest hostGoogle · $0.15 / $1.25OpenAI · $0.05 / $0.25
Hosts on OpenRouter23
Last tested26 Oct 202625 Oct 2026

Compare any two models →

Gemini 3.5 Flash Lite vs GPT-6 Luna: frequently asked questions

Is Gemini 3.5 Flash Lite better than GPT-6 Luna?
On accuracy they are statistically tied: Gemini 3.5 Flash Lite scored 75.0% and GPT-6 Luna 72.5% on the same 80 questions from open datasets. Similar accuracy; GPT-6 Luna costs less per question.
Which is cheaper, Gemini 3.5 Flash Lite or GPT-6 Luna?
GPT-6 Luna is cheaper: $0.00025 per question as billed, against $0.0034. List prices: Gemini 3.5 Flash Lite $0.3 in / $2.5 out, GPT-6 Luna $0.1 in / $0.5 out per million tokens.
Which is faster, Gemini 3.5 Flash Lite or GPT-6 Luna?
Gemini 3.5 Flash Lite is faster at 409 output tokens per second, against 137. Time to first token: 1.1 s for Gemini 3.5 Flash Lite, 1.2 s for GPT-6 Luna.
Which has the larger context window, Gemini 3.5 Flash Lite or GPT-6 Luna?
Both accept about the same amount of context: 1M and 1.1M tokens.