Claude 3 Opus vs GPT-5.5
Compare Claude 3 Opus by Anthropic against GPT-5.5 by OpenAI, context windows of 200K vs 1.1M, tested across 12 shared challenges. Updated April 2026.
Which is better, Claude 3 Opus or GPT-5.5?
Claude 3 Opus and GPT-5.5 are both competitive models. Claude 3 Opus costs $15/M input tokens vs $5/M for GPT-5.5. Context windows: 200K vs 1050K tokens. Compare their real outputs side by side below.
Key Differences Between Claude 3 Opus and GPT-5.5
Claude 3 Opus is made by anthropic while GPT-5.5 is from openai. Claude 3 Opus has a 200K token context window compared to GPT-5.5's 1050K. On pricing, Claude 3 Opus costs $15/M input tokens vs $5/M for GPT-5.5.
API pricing
Per 1M tokens
Claude 3 Opus
Input
$15.00
Output
$75.00
GPT-5.5
Input
$5.00
3.0× cheaper
Output
$30.00
2.5× cheaper
GPT-5.5 is cheaper on both — 3.0× input, 2.5× output
Our Verdict
GPT-5.5
Claude 3 OpusRunner-up
No community votes yet. On paper, GPT-5.5 has the edge — newer, bigger context window.
Too close to call
Writing DNA
Style Comparison
Similarity
46%
GPT-5.5 uses 285.6x more bold
Claude 3 Opus
GPT-5.5
54%Vocabulary58%
14wSentence Length18w
0.48Hedging0.74
0.0Bold2.9
3.0Lists5.1
0.00Emoji0.00
0.00Headings1.68
0.06Transitions0.03
Based on 3 + 26 text responses
FAQ
