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SwapClaude Opus 5.5
Anthropic's new Claude Opus 5.5 writes text and answers questions, offered to developers and paying users, not free to download.
Release page →The basics
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Download
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Per million tokens
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How they score
Combined test score
Epoch Capabilities Index · Epoch AI
Claude Opus 5.5 scores 19 points higher, a big step.
Chat answers, by people's votes
LMArena text, adjusted for style · LMArena
Only Claude Opus 5.5 is in this ranking, which lists the most-voted models.
Building apps, by people's votes
LMArena WebDev · LMArena
In blind votes, people pick Claude Opus 5.5 over GPT-5 about 91% of the time.
Green marks the better of the two on each row, red the other. Rows where one side isn't listed, or where the gap is too close to call, stay plain.
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Rankings from LMArena and Epoch AI, both CC BY 4.0, updated . Developer prices, context windows and knowledge cutoffs from the labs' own listings on models.dev and from OpenRouter. The app links go to each maker's own app when no source says exactly where the model is available.