Claude Opus 4 vs o1
Compare Claude Opus 4 by Anthropic against o1 by OpenAI, context windows of 200K vs 128K, tested across 53 shared challenges. Updated May 2026.
Which is better, Claude Opus 4 or o1?
Claude Opus 4 and o1 are both competitive models. Claude Opus 4 costs $15/M input tokens vs $15/M for o1. Context windows: 200K vs 128K tokens. Compare their real outputs side by side below.
Key Differences Between Claude Opus 4 and o1
Claude Opus 4 is made by anthropic while o1 is from openai. Claude Opus 4 has a 200K token context window compared to o1's 128K. On pricing, Claude Opus 4 costs $15/M input tokens vs $15/M for o1.
API pricing
Per 1M tokens
Claude Opus 4
Input
$15.00
Output
$75.00
o1
Input
$15.00
Output
$60.00
1.3× cheaper
Our Verdict
Claude Opus 4
o1Runner-up
No community votes yet. On paper, Claude Opus 4 has the edge — bigger model tier, newer, bigger context window.
Slight edge
Writing DNA
Style Comparison
Similarity
50%
Claude Opus 4 uses 11.2x more emoji
Claude Opus 4
o1
64%Vocabulary64%
62wSentence Length16w
0.52Hedging0.76
4.4Bold5.0
9.1Lists2.6
0.11Emoji0.00
1.87Headings0.44
0.27Transitions0.40
Based on 16 + 13 text responses
FAQ
