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Model launchPublished 2026-07-05

Claude 4.5 prefers primary sources over aggregators when citing

Anthropic's Claude 4.5 update measurably shifts citation weight toward original research pages and away from aggregator listicles.

By Mark Barclay · Source: Anthropic release notes

Claude 4.5 shipped a new citation heuristic that weights CreativeWork/Dataset schema on the origin page higher than the same content republished on an aggregator. Sites that publish original data with Dataset markup saw a 41% lift in Claude citations week-over-week.

The heuristic also penalises pages whose main content is behind a signup wall or lazy-loaded after user interaction — Claude's crawler treats hidden text as absent.

What to do about it

If you publish research, mark it up with Dataset schema and keep the numbers in the initial HTML, not in a client-only chart component.

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