ChatGPT-4o (March 2025) vs Claude Haiku 4.5
Compare ChatGPT-4o (March 2025) by OpenAI against Claude Haiku 4.5 by Anthropic, context windows of 128K vs 200K, tested across 32 shared challenges.
Our Verdict
ChatGPT-4o (March 2025)
Claude Haiku 4.5
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Claude Haiku 4.5 is 3.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
ChatGPT-4o (March 2025)
Input
$5.00
Output
$15.00
Claude Haiku 4.5
Input
$1.00
5.0× cheaper
Output
$5.00
3.0× cheaper
Claude Haiku 4.5 is cheaper on both — 5.0× input, 3.0× output
Writing DNA
Style Comparison
Similarity
59%
ChatGPT-4o (March 2025) uses 4.6x more emoji
ChatGPT-4o (March 2025)
Claude Haiku 4.5
55%Vocabulary61%
24wSentence Length47w
0.52Hedging0.64
3.3Bold5.1
6.0Lists6.3
0.94Emoji0.20
0.63Headings2.46
0.05Transitions0.17
Based on 15 + 24 text responses
Research
What we learned reading every model
FAQ
