In the context of URLs, “canonical” refers to the preferred or master version of a web page. It is the URL that search engines should consider as the primary source when multiple pages have similar or duplicate content.
You can check if a URL is canonical by inspecting the page source and searching for the rel=”canonical” tag within the <head> section. Alternatively, you can examine the HTTP headers of the page and look for the “Link” header containing the rel=”canonical” attribute.
Canonical URLs are necessary when a website has multiple pages with similar or duplicate content. They help prevent duplicate content issues, specify the preferred URL for search results, consolidate link signals, and simplify tracking metrics.
While you can specify the canonical URL for a page, search engines may choose to ignore it if they determine that a different URL is more relevant or authoritative. However, in most cases, search engines will respect the specified canonical URL if it is implemented correctly and aligns with their guidelines.
Canonical URLs and 301 redirects serve different purposes. Canonical URLs are used to specify the preferred version of a page when multiple pages have similar or duplicate content, while 301 redirects are used to permanently redirect users and search engines from one URL to another. In some cases, using a 301 redirect to the canonical URL can be a more definitive way of consolidating link equity and avoiding duplicate content issues.