ID/SID URLs

1 - Findings & Impacts

Duplicate content is one of the most penalizing principles to be able to rank on a search engine like Google. We speak of duplication of content when content on several pages belonging or not to the same domain are identical or substantially similar.

This problem can also come from a site generating URLs with session IDs. Example:

As the identifier may change with each new session or each new user, the risk of seeing your page being multiplied for each exploration of Googlebot is very dangerous as it will impact both crawl budget/credit and create duplicated content.

2 - Recommendations

A page must have one and only URL. Never use session IDs n the URL parameters, use cookies instead.