Gemini 1.5 Pro vs Gemini 2.5 Pro Preview 06-05

Compare Gemini 1.5 Pro and Gemini 2.5 Pro Preview 06-05, both from Google AI, context windows of 1.0M vs 1.0M, tested across 13 shared challenges. Updated April 2026.

Which is better, Gemini 1.5 Pro or Gemini 2.5 Pro Preview 06-05?

Gemini 1.5 Pro and Gemini 2.5 Pro Preview 06-05 are both competitive models. Gemini 1.5 Pro costs $3.5/M input tokens vs $1.25/M for Gemini 2.5 Pro Preview 06-05. Context windows: 1000K vs 1049K tokens. Compare their real outputs side by side below.

Key Differences Between Gemini 1.5 Pro and Gemini 2.5 Pro Preview 06-05

Gemini 1.5 Pro is made by google while Gemini 2.5 Pro Preview 06-05 is from google. Gemini 1.5 Pro has a 1000K token context window compared to Gemini 2.5 Pro Preview 06-05's 1049K. On pricing, Gemini 1.5 Pro costs $3.5/M input tokens vs $1.25/M for Gemini 2.5 Pro Preview 06-05.

Our Verdict
Gemini 2.5 Pro Preview 06-05
Gemini 2.5 Pro Preview 06-05
Gemini 1.5 Pro
Gemini 1.5 ProRunner-up

No community votes yet. On paper, Gemini 2.5 Pro Preview 06-05 has the edge — bigger model tier, newer.

Too close to call
Writing DNA

Style Comparison

Similarity
100%

Gemini 2.5 Pro Preview 06-05 uses 12.2x more headings

Gemini 1.5 Pro
Gemini 2.5 Pro Preview 06-05
61%Vocabulary51%
15wSentence Length15w
0.80Hedging0.31
3.7Bold4.8
3.3Lists4.1
0.00Emoji0.00
0.08Headings0.98
0.09Transitions0.05
Based on 8 + 20 text responses
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279 AI models invented the same fake scientist.

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