Claude Sonnet 4.5 vs GPT-5.1
Compare Claude Sonnet 4.5 by Anthropic against GPT-5.1 by OpenAI, in 26 community votes, claude sonnet 4.5 wins 55% of head-to-head duels, context windows of 200K vs 400K, tested across 43 shared challenges.
Web Design: Claude Sonnet 4.5 wins 67% of votes
Reasoning: Claude Sonnet 4.5 wins 57% of votes
Conversation: Claude Sonnet 4.5 and GPT-5.1 are tied
Analysis: GPT-5.1 wins 100% of votes
Image Generation: Claude Sonnet 4.5 and GPT-5.1 are tied
Our Verdict
Claude Sonnet 4.5Winner
GPT-5.1Runner-up
Claude Sonnet 4.5 has the edge overall. In 26 blind votes, Claude Sonnet 4.5 wins 55% of the time.
Pick Claude Sonnet 4.5 for Web Design, Reasoning. Pick GPT-5.1 for Analysis.
Slight edge
API pricing
Cost per 1M tokens
Claude Sonnet 4.5
Input
$3.00
Output
$15.00
GPT-5.1
Input
$1.25
2.4× cheaper
Output
$10.00
1.5× cheaper
GPT-5.1 is cheaper on both — 2.4× input, 1.5× output
Writing DNA
Style Comparison
Similarity
63%
Claude Sonnet 4.5 uses 45.2x more emoji
Claude Sonnet 4.5
GPT-5.1
64%Vocabulary62%
94wSentence Length19w
0.48Hedging0.29
4.9Bold3.5
8.0Lists7.2
0.45Emoji0.00
1.91Headings0.61
0.07Transitions0.03
Based on 20 + 14 text responses
Research
What we learned reading every model
FAQ
