Gemini 1.5 Pro vs GPT-5

Compare Gemini 1.5 Pro by Google AI against GPT-5 by OpenAI, context windows of 1.0M vs 400K, tested across 19 shared challenges. Updated April 2026.

Which is better, Gemini 1.5 Pro or GPT-5?

Gemini 1.5 Pro and GPT-5 are both competitive models. Gemini 1.5 Pro costs $3.5/M input tokens vs $1.25/M for GPT-5. Context windows: 1000K vs 400K tokens. Compare their real outputs side by side below.

Key Differences Between Gemini 1.5 Pro and GPT-5

Gemini 1.5 Pro is made by google while GPT-5 is from openai. Gemini 1.5 Pro has a 1000K token context window compared to GPT-5's 400K. On pricing, Gemini 1.5 Pro costs $3.5/M input tokens vs $1.25/M for GPT-5.

Our Verdict
GPT-5
GPT-5
Gemini 1.5 Pro
Gemini 1.5 ProRunner-up

No community votes yet. On paper, GPT-5 has the edge — bigger model tier, newer.

Too close to call
Writing DNA

Style Comparison

Similarity
99%

Gemini 1.5 Pro uses 19.4x more bold

Gemini 1.5 Pro
GPT-5
61%Vocabulary65%
15wSentence Length13w
0.80Hedging0.20
3.7Bold0.2
3.3Lists4.6
0.00Emoji0.00
0.08Headings0.16
0.09Transitions0.03
Based on 8 + 16 text responses
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Gemini 1.5 ProGPT-5

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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