ChatGPT-4o (March 2025)vsGemini 2.5 Flash Preview 09-2025
Gemini 2.5 Flash Preview 09-2025 is cheaper than ChatGPT-4o (March 2025) at $0.3/M vs $5/M input tokens.
| Spec | ChatGPT-4o (March 2025) | Gemini 2.5 Flash Preview 09-2025 |
|---|---|---|
| Input price | $5/M tokens | $0.3/M tokens |
| Output price | $15/M tokens | $2.5/M tokens |
| Context window | 128K tokens | 1.0M tokens |
| Released | Mar 2025 | Sep 2025 |
Our Verdict
Gemini 2.5 Flash Preview 09-2025
ChatGPT-4o (March 2025)Runner-up
Not enough votes to call it. On the specs, Gemini 2.5 Flash Preview 09-2025 has the edge: newer, bigger context window.
Gemini 2.5 Flash Preview 09-2025 costs 6.0x less per token.
Too close to call
API pricing
Cost per 1M tokens
ChatGPT-4o (March 2025)
Input
$5.00
Output
$15.00
Gemini 2.5 Flash Preview 09-2025
Input
$0.30
17× cheaper
Output
$2.50
6.0× cheaper
Gemini 2.5 Flash Preview 09-2025 is cheaper on both — 17× input, 6.0× output
Writing DNA
Style Comparison
Similarity
41%
ChatGPT-4o (March 2025) uses 7.0x more emoji
ChatGPT-4o (March 2025)
Gemini 2.5 Flash Preview 09-2025
55%Vocabulary53%
24wSentence Length19w
0.52Hedging0.30
3.3Bold5.8
6.0Lists3.1
0.94Emoji0.14
0.63Headings0.93
0.05Transitions0.22
Based on 15 + 22 text responses
Research
What we learned reading every model
FAQ
Common questions
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