Claude Opus 4.5 vs OpenAI o4-mini
Compare Claude Opus 4.5 by Anthropic against OpenAI o4-mini by OpenAI, tested across 54 shared challenges. Updated June 2026.
Which is better, Claude Opus 4.5 or OpenAI o4-mini?
Claude Opus 4.5 and OpenAI o4-mini are both competitive models. Compare their real outputs side by side below.
Key Differences Between Claude Opus 4.5 and OpenAI o4-mini
Claude Opus 4.5 is made by anthropic while OpenAI o4-mini is from openai.
Our Verdict
Claude Opus 4.5
OpenAI o4-miniRunner-up
No community votes yet. On paper, Claude Opus 4.5 has the edge — bigger model tier, newer.
Too close to call
API pricing
Cost per 1M tokens
Claude Opus 4.5
Input
—
Output
—
OpenAI o4-mini
Input
$1.10
Output
$4.40
Writing DNA
Style Comparison
Similarity
49%
Claude Opus 4.5 uses 580.0x more bold
Claude Opus 4.5
OpenAI o4-mini
64%Vocabulary73%
55wSentence Length15w
0.86Hedging0.18
5.8Bold0.0
4.5Lists2.1
0.15Emoji0.00
1.59Headings0.00
0.05Transitions0.02
Based on 24 + 10 text responses
Research
What we learned reading every model
FAQ
