Gemini 3 Flash Preview vs GPT-5.1-Codex
Compare Gemini 3 Flash Preview by Google AI against GPT-5.1-Codex by OpenAI, context windows of 1.0M vs 400K, tested across 53 shared challenges.
Our Verdict
Gemini 3 Flash Preview
GPT-5.1-Codex
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Gemini 3 Flash Preview is 3.3x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Gemini 3 Flash Preview
Input
$0.50
2.5× cheaper
Output
$3.00
3.3× cheaper
GPT-5.1-Codex
Input
$1.25
Output
$10.00
Gemini 3 Flash Preview is cheaper on both — 2.5× input, 3.3× output
Writing DNA
Style Comparison
Similarity
39%
GPT-5.1-Codex uses 5.2x more transitions
Gemini 3 Flash Preview
GPT-5.1-Codex
55%Vocabulary70%
18wSentence Length17w
0.42Hedging0.39
7.1Bold3.4
4.5Lists3.5
0.00Emoji0.00
0.84Headings0.50
0.07Transitions0.38
Based on 24 + 14 text responses
Research
What we learned reading every model
FAQ
