Duplicate content
Duplicate content exposes the same or nearly the same material at more than one URL.
How it works
Crawlers cluster similar representations and choose a canonical using redirects, link signals, sitemap entries, declarations, and content comparison.
How to validate it
Inventory normalized hashes by URL, identify intended variants, and make canonical and internal-link signals consistent.
Common failure
Parameter combinations and printer views can multiply one article into thousands of crawlable addresses.
Machine-readable editions
The same article is available as Markdown and JSON. These alternates are linked here but are not submitted through the sitemap or IndexNow.