How to choose a canonical URL
A simple decision framework for picking the preferred version when more than one URL can represent the same page.
The best canonical URL is usually the cleanest version of the page that matches how you want people and search systems to find it. That often means the HTTPS version, the preferred host, and the final URL structure you actually want to maintain long term.
A useful test is to ask whether the alternate URL changes the page's real purpose or only its presentation. If the content intent is the same, the canonical should usually point to the preferred version instead of leaving the decision open to interpretation.
Choosing a canonical URL gets much easier when redirects, internal links, and sitemap entries all reinforce the same option. The canonical tag then becomes a confirmation signal rather than the only thing holding the URL strategy together.
Use this guide when you want a little more context before publishing, need a quick refresher on best practices, or want to avoid the mistakes that commonly lead to crawl or indexing issues later.
If you want to apply this advice immediately, use the related tool and compare the output against the points covered in this guide.