Claude Sonnet 4.5 vs OpenAI o3
Compare Claude Sonnet 4.5 by Anthropic against OpenAI o3 by OpenAI, in 2 community votes, claude sonnet 4.5 wins 100% of head-to-head duels, tested across 43 shared challenges.
Our Verdict
Claude Sonnet 4.5Winner
OpenAI o3Runner-up
Pick Claude Sonnet 4.5. In 2 blind votes, Claude Sonnet 4.5 wins 100% of the time. That's not luck.
Clear winner
API pricing
Cost per 1M tokens
Claude Sonnet 4.5
Input
$3.00
3.3× cheaper
Output
$15.00
2.7× cheaper
OpenAI o3
Input
$10.00
Output
$40.00
Claude Sonnet 4.5 is cheaper on both — 3.3× input, 2.7× output
Writing DNA
Style Comparison
Similarity
42%
Claude Sonnet 4.5 uses 45.2x more emoji
Claude Sonnet 4.5
OpenAI o3
64%Vocabulary68%
94wSentence Length14w
0.48Hedging0.26
4.9Bold0.7
8.0Lists3.0
0.45Emoji0.00
1.91Headings0.38
0.07Transitions0.12
Based on 20 + 16 text responses
Research
What we learned reading every model
FAQ
