Gemini 3 Pro Preview vs o3 Mini

Compare Gemini 3 Pro Preview by Google AI against o3 Mini by OpenAI, tested across 51 shared challenges. Updated April 2026.

Which is better, Gemini 3 Pro Preview or o3 Mini?

Gemini 3 Pro Preview and o3 Mini are both competitive models. Compare their real outputs side by side below.

Key Differences Between Gemini 3 Pro Preview and o3 Mini

Gemini 3 Pro Preview is made by google while o3 Mini is from openai.

Our Verdict
Gemini 3 Pro Preview
Gemini 3 Pro Preview
o3 Mini
o3 MiniRunner-up

No community votes yet. On paper, Gemini 3 Pro Preview has the edge — bigger model tier, newer.

Too close to call
Writing DNA

Style Comparison

Similarity
97%

Gemini 3 Pro Preview uses 2.8x more lists

Gemini 3 Pro Preview
o3 Mini
58%Vocabulary65%
17wSentence Length17w
0.37Hedging0.74
7.7Bold3.9
4.8Lists1.7
0.00Emoji0.00
0.90Headings0.47
0.25Transitions0.38
Based on 23 + 12 text responses
vs

Ask them anything yourself

Gemini 3 Pro Previewo3 Mini

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
FAQ

Common questions