Claude Sonnet 5 vs OpenAI o3
Compare Claude Sonnet 5 by Anthropic against OpenAI o3 by OpenAI, tested across 53 shared challenges.
Our Verdict
Claude Sonnet 5
OpenAI o3
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Claude Sonnet 5 is 4.0x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Claude Sonnet 5
Input
$2.00
5.0× cheaper
Output
$10.00
4.0× cheaper
OpenAI o3
Input
$10.00
Output
$40.00
Claude Sonnet 5 is cheaper on both — 5.0× input, 4.0× output
Writing DNA
Style Comparison
Similarity
51%
Claude Sonnet 5 uses 79.4x more emoji
Claude Sonnet 5
OpenAI o3
59%Vocabulary68%
35wSentence Length14w
0.53Hedging0.26
3.5Bold0.7
3.5Lists3.0
0.79Emoji0.00
1.25Headings0.38
0.06Transitions0.12
Based on 27 + 16 text responses
Research
What we learned reading every model
FAQ
