Gemini 2.5 Pro Preview 06-05 vs GPT-5 Codex

Compare Gemini 2.5 Pro Preview 06-05 by Google AI against GPT-5 Codex by OpenAI, tested across 34 shared challenges. Updated April 2026.

Which is better, Gemini 2.5 Pro Preview 06-05 or GPT-5 Codex?

Gemini 2.5 Pro Preview 06-05 and GPT-5 Codex are both competitive models. Compare their real outputs side by side below.

Key Differences Between Gemini 2.5 Pro Preview 06-05 and GPT-5 Codex

Gemini 2.5 Pro Preview 06-05 is made by google while GPT-5 Codex is from openai.

Our Verdict
Gemini 2.5 Pro Preview 06-05
Gemini 2.5 Pro Preview 06-05
GPT-5 Codex
GPT-5 Codex

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call
Writing DNA

Style Comparison

Similarity
100%

GPT-5 Codex uses 14.6x more emoji

Gemini 2.5 Pro Preview 06-05
GPT-5 Codex
51%Vocabulary64%
15wSentence Length17w
0.31Hedging0.38
4.8Bold2.3
4.1Lists3.5
0.00Emoji0.15
0.98Headings0.49
0.05Transitions0.05
Based on 20 + 13 text responses
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Gemini 2.5 Pro Preview 06-05GPT-5 Codex

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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