A canonical URL tells search engines which version of a page is the authoritative one. It’s a short line in your HTML:
<link rel="canonical" href="https://example.com/page-name" />
This matters because the same page content can often be reached via multiple URLs. For example:
https://example.com/pagehttps://example.com/page/https://example.com/page?utm_source=newsletterhttps://www.example.com/page
Without a canonical tag, search engines may treat these as four separate pages competing for the same ranking, which dilutes the SEO value of all of them.
Most WordPress SEO plugins (Yoast, Rank Math, All in One SEO) set canonical tags automatically for every page, using the cleanest version of the URL. If you’re not running one, your theme may or may not handle this correctly.
It’s a small fix with surprisingly large ranking implications on sites that get a lot of traffic with URL parameters attached.
