Duplicate content

Duplicate content means substantial blocks of text that appear at more than one web address. It can be inside your own site, for example from tracking parameters or printer versions, or across sites when content is copied or syndicated.

Google has said there's no general penalty for duplicate content. The practical problem is that search engines have to pick one version, and may pick the wrong one. Links and signals can also split across copies. Deliberately copying content at scale to manipulate results is a different matter and can be treated as spam.

Practical point: use canonical tags or 301 redirects to point duplicates to the main version, and keep one clear URL for each page. If you syndicate content, ask the other site to add a canonical tag pointing to your original. Find internal duplicates with a site crawl and fix the most important ones first.