Claude Sonnet 4.5 vs GPT-5 Pro

Compare Claude Sonnet 4.5 by Anthropic against GPT-5 Pro by OpenAI, in 17 community votes, claude sonnet 4.5 wins 63% of head-to-head duels, context windows of 200K vs 400K, tested across 36 shared challenges. Updated April 2026.

Which is better, Claude Sonnet 4.5 or GPT-5 Pro?

Claude Sonnet 4.5 is the better choice overall, winning 63% of 17 blind community votes on Rival. Claude Sonnet 4.5 costs $3/M input tokens vs $15/M for GPT-5 Pro. Context windows: 200K vs 400K tokens. Compare their real outputs side by side below.

Key Differences Between Claude Sonnet 4.5 and GPT-5 Pro

Claude Sonnet 4.5 is made by anthropic while GPT-5 Pro is from openai. Claude Sonnet 4.5 has a 200K token context window compared to GPT-5 Pro's 400K. On pricing, Claude Sonnet 4.5 costs $3/M input tokens vs $15/M for GPT-5 Pro. In community voting, In 17 community votes, Claude Sonnet 4.5 wins 63% of head-to-head duels.

In 17 community votes, Claude Sonnet 4.5 wins 63% of head-to-head duels. Claude Sonnet 4.5 leads in Web Design, Analysis, Conversation, while GPT-5 Pro leads in Reasoning, Image Generation. Based on blind community voting from the Rival open dataset of 17+ human preference judgments for this pair.

Reasoning: GPT-5 Pro wins 60% of votes
Web Design: Claude Sonnet 4.5 wins 75% of votes
Image Generation: GPT-5 Pro wins 67% of votes
Analysis: Claude Sonnet 4.5 wins 100% of votes
Conversation: Claude Sonnet 4.5 wins 100% of votes
Our Verdict
Claude Sonnet 4.5
Claude Sonnet 4.5Winner
GPT-5 Pro
GPT-5 ProRunner-up

Pick Claude Sonnet 4.5. In 17 blind votes, Claude Sonnet 4.5 wins 63% of the time. That's not luck.

Pick Claude Sonnet 4.5 for Analysis, Conversation, Web Design. Pick GPT-5 Pro for Image Generation, Reasoning. Claude Sonnet 4.5 is 8.0x cheaper per token — worth considering if cost matters.

Clear winner
Writing DNA

Style Comparison

Similarity
91%

Claude Sonnet 4.5 uses 490.1x more bold

Claude Sonnet 4.5
GPT-5 Pro
64%Vocabulary65%
94wSentence Length15w
0.48Hedging0.32
4.9Bold0.0
8.0Lists2.9
0.45Emoji0.00
1.91Headings0.00
0.07Transitions0.01
Based on 20 + 11 text responses
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Claude Sonnet 4.5GPT-5 Pro

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