Gemini 2.5 Flash Preview (thinking) vs GPT-5

Compare Gemini 2.5 Flash Preview (thinking) by Google AI against GPT-5 by OpenAI, in 2 community votes, gpt-5 wins 100% of head-to-head duels, context windows of 1.0M vs 400K, tested across 20 shared challenges. Updated April 2026.

Which is better, Gemini 2.5 Flash Preview (thinking) or GPT-5?

GPT-5 is the better choice overall, winning 100% of 2 blind community votes on Rival. Gemini 2.5 Flash Preview (thinking) costs $0.175/M input tokens vs $1.25/M for GPT-5. Context windows: 1049K vs 400K tokens. Compare their real outputs side by side below.

Key Differences Between Gemini 2.5 Flash Preview (thinking) and GPT-5

Gemini 2.5 Flash Preview (thinking) is made by google while GPT-5 is from openai. Gemini 2.5 Flash Preview (thinking) has a 1049K token context window compared to GPT-5's 400K. On pricing, Gemini 2.5 Flash Preview (thinking) costs $0.175/M input tokens vs $1.25/M for GPT-5. In community voting, In 2 community votes, GPT-5 wins 100% of head-to-head duels.

In 2 community votes, GPT-5 wins 100% of head-to-head duels. Based on blind community voting from the Rival open dataset of 2+ human preference judgments for this pair.

Our Verdict
GPT-5
GPT-5Winner
Gemini 2.5 Flash Preview (thinking)
Gemini 2.5 Flash Preview (thinking)Runner-up

Pick GPT-5. In 2 blind votes, GPT-5 wins 100% of the time. That's not luck.

Clear winner
Writing DNA

Style Comparison

Similarity
100%

GPT-5 uses 16.2x more headings

Gemini 2.5 Flash Preview (thinking)
GPT-5
53%Vocabulary65%
14wSentence Length13w
0.38Hedging0.20
4.4Bold0.2
4.1Lists4.6
0.00Emoji0.00
0.00Headings0.16
0.24Transitions0.03
Based on 7 + 16 text responses
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Gemini 2.5 Flash Preview (thinking)GPT-5

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