Identify preferred URLs and find canonical mistakes caused by domains, language versions and parameters across similar pages.
When content opens at multiple addresses, identify its preferred URL. Tracking parameters may leave a service page unchanged. Pointing every page's canonical to the home page is not a suitable solution.
Compare the actual content
A tracking version of a product URL differs from two pages describing separate services. Similar layouts do not establish equivalence. Consider the topic and the answer provided to the visitor.
Verify the destination
The canonical target should work and contain the intended content. Check for temporary domains, incorrect protocols, outdated paths and wrong language versions. Internal links should generally use the preferred URL too.
Understand its limits
Google treats canonical information as a signal rather than an instruction it must accept. Keep redirects, sitemap entries and canonical declarations consistent instead of sending conflicting preferences.
Test individual pages
A correct home page does not prove article canonicals are correct. Inspect categories, several posts and both language versions. Repeat the review when adding a content type or pagination.