Duplicate content
Substantively identical or near-identical content available at more than one URL, within a site or across sites.
AlgorithmsDuplicate filtering
Deduplication system
Google's system for ensuring results are not dominated by near-identical pages, filtering duplicates so users see a varied set of sources.
In full
Listed among Google's ranking systems, deduplication operates both at the clustering stage, where duplicate URLs are consolidated to a canonical, and at the result stage, where similar pages are filtered from the SERP. It is why syndicated copies of the same article rarely appear together, and why near-duplicate internal pages simply do not both surface. It also interacts with the site diversity system.
Example
A press release published by twelve outlets shows only one or two versions in the results, with the rest filtered.
Related terms
Canonicalization
The process by which a search engine groups duplicate or near-duplicate URLs into a cluster and picks one representative URL to index and…
Site diversity system
Google's system limiting how many results from the same site appear for a query, typically to two, so results are not dominated by one…
Content syndication
Republishing the same content on third-party sites for reach; without correct canonicalisation it creates duplicates that can outrank the…
Google ranking systems
Google's documented list of the systems that generate rankings, distinguished from one-off 'updates' to those systems, and including…