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GPT-4.5 vs Claude Opus 4

Compare GPT-4.5 by OpenAI against Claude Opus 4 by Anthropic, in 90 community votes, claude opus 4 wins 85% of head-to-head duels, context windows of 128K vs 200K, tested across 17 shared challenges. Updated April 2026.

Which is better, GPT-4.5 or Claude Opus 4?

Claude Opus 4 is the better choice overall, winning 85% of 90 blind community votes on Rival. GPT-4.5 costs $75/M input tokens vs $15/M for Claude Opus 4. Context windows: 128K vs 200K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-4.5 and Claude Opus 4

GPT-4.5 is made by openai while Claude Opus 4 is from anthropic. GPT-4.5 has a 128K token context window compared to Claude Opus 4's 200K. On pricing, GPT-4.5 costs $75/M input tokens vs $15/M for Claude Opus 4. In community voting, In 90 community votes, Claude Opus 4 wins 85% of head-to-head duels.

In 90 community votes, Claude Opus 4 wins 85% of head-to-head duels. Claude Opus 4 leads in Web Design, Image Generation, Conversation. Based on blind community voting from the Rival open dataset of 90+ human preference judgments for this pair.

Web Design: Claude Opus 4 wins 82% of votes
Image Generation: Claude Opus 4 wins 84% of votes
Conversation: Claude Opus 4 wins 100% of votes
Reasoning: Claude Opus 4 wins 71% of votes
Our Verdict
Claude Opus 4
Claude Opus 4Winner
GPT-4.5
GPT-4.5Runner-up

Pick Claude Opus 4. In 90 blind votes, Claude Opus 4 wins 85% of the time. That's not luck.

Claude Opus 4 particularly excels in Conversation, Image Generation, Web Design.

Clear winner
Writing DNA

Style Comparison

Similarity
98%

Claude Opus 4 uses 11.2x more emoji

GPT-4.5
Claude Opus 4
63%Vocabulary64%
16wSentence Length62w
0.57Hedging0.52
4.7Bold4.4
6.4Lists9.1
0.00Emoji0.11
1.30Headings1.87
0.54Transitions0.27
Based on 11 + 16 text responses
vs

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GPT-4.5Claude Opus 4

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
Free preview13 of 58 slides
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