What is duplicate content?

Duplicate content means the same or nearly the same content lives at several addresses. Usually it isn't deliberate: http and https, www and non-www versions, filter and sort parameters (?color=blue), print pages, one product reachable under several category URLs. Text copied from other sites also counts.

#Why it matters

• Google generally doesn't penalise duplicate content; it picks one of the similar pages and groups the rest. The problem is that it may not pick the one you want.
• Links and signals get split across several URLs.
• Crawl budget is spent on variations of the same content.

#Where you see it in SEOAsist

SEOAsist doesn't run a separate test comparing page texts against each other. The most common symptoms of duplication are caught in Technical Audit:

• Duplicate title and Duplicate meta description: the same title or description on several pages.
• No canonical tag and Canonical points to another page: the preferred URL isn't declared, or points somewhere unexpected.

With Search Console connected, SEO analysis also lists URLs where Google chose a different canonical than the one you declared. More: Technical audit.

#Example

Parameter-filtered pages pointing to the main category as canonical:

<!-- on https://examplefurniture.com/dining-tables?sort=price -->
<link rel="canonical" href="https://examplefurniture.com/dining-tables">

#Common mistakes

• Not 301-redirecting every version (http/https, www) to a single address.
• Using the manufacturer's product description as is; the same text exists on hundreds of sites.
• Trying to solve duplication with robots.txt; Google can't see the canonical on a blocked page.
• Putting a canonical to the home page on every page.