ResearchLLM Verifications Leaderboard

Data as of · 78 models, 80 questions · reviewed by Suhas Bhairav · methodology

Head to head · tested 27 Oct 2026

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash Lite: accuracy, speed and price

Similar accuracy; Gemini 3.5 Flash Lite costs less per question.

GoogleGemini 3.1 Pro Preview77.5% score · #9$0.017 per question124 tok/sGoogleGemini 3.5 Flash Lite75.0% score · #15$0.0034 per question409 tok/s

Verdict

Built from the measurements below

  • Accuracy is too close to call: Gemini 3.1 Pro Preview scored 77.5% and Gemini 3.5 Flash Lite 75.0% on the same 80 questions, a gap within what chance alone could produce.
  • Gemini 3.5 Flash Lite is 5.1× cheaper per question as billed ($0.0034 vs $0.017), reasoning tokens included.
  • Gemini 3.5 Flash Lite generates text 3.3× faster: 409 tokens per second against 124.
  • Gemini 3.5 Flash Lite starts answering sooner: 1.1 s to the first token, against 3.4 s for Gemini 3.1 Pro Preview.

Which should you choose?

Choose Gemini 3.5 Flash Lite for the lower cost per correct answer ($0.0045 against $0.022), faster streaming and a quicker first token.

Accuracy gap +2.5 points (z = 0.37). 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 3.1 Pro PreviewGemini 3.5 Flash LiteEdge
Verification scoreHigher is better77.5%75.0%Too close to call
Cost per questionLower is better$0.017$0.0034Gemini 3.5 Flash Lite
Output speedHigher is better124409Gemini 3.5 Flash Lite
Time to first tokenLower is better3.4 s1.1 sGemini 3.5 Flash Lite
End-to-end response timeLower is better8.9 s2.8 sGemini 3.5 Flash Lite
Tokens per questionLower is better1,3821,311Similar
Context windowHigher is better1M1MSimilar

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 3.1 Pro Preview first, Gemini 3.5 Flash Lite second

Verification scorehigher is better
Gemini 3.1 Pro Preview77.5%
Gemini 3.5 Flash Lite75.0%
Cost per questionlower is better
Gemini 3.1 Pro Preview$0.017
Gemini 3.5 Flash Lite$0.0034
Output speedhigher is better
Gemini 3.1 Pro Preview124
Gemini 3.5 Flash Lite409
Time to first tokenlower is better
Gemini 3.1 Pro Preview3.4 s
Gemini 3.5 Flash Lite1.1 s
End-to-end response timelower is better
Gemini 3.1 Pro Preview8.9 s
Gemini 3.5 Flash Lite2.8 s
Tokens per questionlower is better
Gemini 3.1 Pro Preview1,382
Gemini 3.5 Flash Lite1,311
Context windowhigher is better
Gemini 3.1 Pro Preview1M
Gemini 3.5 Flash Lite1M

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 3.1 Pro PreviewGemini 3.5 Flash Lite
CreatorGoogleGoogle
Released19 Feb 202621 Jul 2026
Weights——
ReasoningYesYes
Inputaudio, file, image, text, videotext, image, video, file, audio
Outputtexttext
Context window1M tokens1M tokens
Knowledge cutoff——
List price in / out per 1M$2 / $12$0.3 / $2.5
Blended price per 1M (3:1)$4.50$0.85
Cheapest hostGoogle · $1 / $6Google · $0.15 / $1.25
Hosts on OpenRouter22
Last tested26 Oct 202626 Oct 2026

Compare any two models →

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash Lite: frequently asked questions

Is Gemini 3.1 Pro Preview better than Gemini 3.5 Flash Lite?
On accuracy they are statistically tied: Gemini 3.1 Pro Preview scored 77.5% and Gemini 3.5 Flash Lite 75.0% on the same 80 questions from open datasets. Similar accuracy; Gemini 3.5 Flash Lite costs less per question.
Which is cheaper, Gemini 3.1 Pro Preview or Gemini 3.5 Flash Lite?
Gemini 3.5 Flash Lite is cheaper: $0.0034 per question as billed, against $0.017. List prices: Gemini 3.1 Pro Preview $2 in / $12 out, Gemini 3.5 Flash Lite $0.3 in / $2.5 out per million tokens.
Which is faster, Gemini 3.1 Pro Preview or Gemini 3.5 Flash Lite?
Gemini 3.5 Flash Lite is faster at 409 output tokens per second, against 124. Time to first token: 3.4 s for Gemini 3.1 Pro Preview, 1.1 s for Gemini 3.5 Flash Lite.
Which has the larger context window, Gemini 3.1 Pro Preview or Gemini 3.5 Flash Lite?
Both accept about the same amount of context: 1M and 1M tokens.