Gemini 3 Flash Preview vs OpenAI o3

Compare Gemini 3 Flash Preview by Google AI against OpenAI o3 by OpenAI, tested across 54 shared challenges. Updated April 2026.

Which is better, Gemini 3 Flash Preview or OpenAI o3?

Gemini 3 Flash Preview and OpenAI o3 are both competitive models. Gemini 3 Flash Preview costs $0.5/M input tokens vs $10/M for OpenAI o3. Compare their real outputs side by side below.

Key Differences Between Gemini 3 Flash Preview and OpenAI o3

Gemini 3 Flash Preview is made by google while OpenAI o3 is from openai. On pricing, Gemini 3 Flash Preview costs $0.5/M input tokens vs $10/M for OpenAI o3.

Our Verdict
Gemini 3 Flash Preview
Gemini 3 Flash Preview
OpenAI o3
OpenAI o3

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 13x cheaper per token — worth considering if cost matters.

Too close to call
Writing DNA

Style Comparison

Similarity
96%

Gemini 3 Flash Preview uses 10.2x more bold

Gemini 3 Flash Preview
OpenAI o3
55%Vocabulary68%
18wSentence Length14w
0.42Hedging0.26
7.1Bold0.7
4.5Lists3.0
0.00Emoji0.00
0.84Headings0.38
0.07Transitions0.12
Based on 24 + 16 text responses
vs

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Gemini 3 Flash PreviewOpenAI o3

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
Free preview13 of 58 slides
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