Claude Opus 4.8 vs GPT-5.3-Codex
Compare Claude Opus 4.8 by Anthropic against GPT-5.3-Codex by OpenAI, in 2 community votes, gpt-5.3-codex wins 100% of head-to-head duels, context windows of 1.0M vs 400K, tested across 53 shared challenges.
Our Verdict
GPT-5.3-CodexWinner
Claude Opus 4.8Runner-up
Pick GPT-5.3-Codex. In 2 blind votes, GPT-5.3-Codex wins 100% of the time. That's not luck.
Clear winner
API pricing
Cost per 1M tokens
Claude Opus 4.8
Input
$5.00
Output
$25.00
GPT-5.3-Codex
Input
$1.75
2.9× cheaper
Output
$14.00
1.8× cheaper
GPT-5.3-Codex is cheaper on both — 2.9× input, 1.8× output
Writing DNA
Style Comparison
Similarity
62%
Claude Opus 4.8 uses 4.9x more emoji
Claude Opus 4.8
GPT-5.3-Codex
60%Vocabulary65%
19wSentence Length23w
0.46Hedging0.51
4.7Bold6.5
3.2Lists6.2
0.78Emoji0.16
1.15Headings1.90
0.04Transitions0.03
Based on 27 + 23 text responses
Research
What we learned reading every model
FAQ
