Claude Sonnet 4.5 vs OpenAI o4-mini
Compare Claude Sonnet 4.5 by Anthropic against OpenAI o4-mini by OpenAI, tested across 43 shared challenges.
Our Verdict
Claude Sonnet 4.5
OpenAI o4-miniRunner-up
No community votes yet. On paper, Claude Sonnet 4.5 has the edge — bigger model tier, newer, bigger context window.
OpenAI o4-mini is 3.4x cheaper per token — worth considering if cost matters.
Too close to call
API pricing
Cost per 1M tokens
Claude Sonnet 4.5
Input
$3.00
Output
$15.00
OpenAI o4-mini
Input
$1.10
2.7× cheaper
Output
$4.40
3.4× cheaper
OpenAI o4-mini is cheaper on both — 2.7× input, 3.4× output
Writing DNA
Style Comparison
Similarity
51%
Claude Sonnet 4.5 uses 490.1x more bold
Claude Sonnet 4.5
OpenAI o4-mini
64%Vocabulary73%
94wSentence Length15w
0.48Hedging0.18
4.9Bold0.0
8.0Lists2.1
0.45Emoji0.00
1.91Headings0.00
0.07Transitions0.02
Based on 20 + 10 text responses
Research
What we learned reading every model
FAQ
