Canonical Tag Generator

It fetches the URL server side, follows any redirects, and reads the link rel=canonical element out of the returned HTML. You see the declared canonical if one exists, plus the final URL, which becomes the suggested value when nothing is declared.

Absolute, always. Relative canonicals are technically parseable but they inherit whatever protocol and host the page was served on, which reintroduces the http versus https ambiguity you were trying to remove. The tool's helper text recommends absolute URLs for exactly this reason.

Yes, cross-domain canonicals are valid and Google honors them when the content matches. Syndication is the classic case: the republished copy canonicals back to the original so the source keeps the ranking signals.

Because a page with no canonical leaves the choice entirely to Google, and Google sometimes picks a parameterized or paginated variant you'd never choose yourself. The warning is your cue to add a tag, even a self-referencing one, so your preference is on record.

No, it's a strong hint, not a command. Google can override it when signals conflict, for example when the canonical target redirects away or the two pages differ too much. Consistent internal links and sitemap entries pointing at the same URL make the hint much harder to ignore.

Exactly one. If Google finds two or more rel canonical elements with different targets, it typically ignores all of them, which is worse than having none. Check your theme and SEO plugin aren't both injecting one before you add the generated tag.

It's good practice. A self-referencing canonical protects you from parameters other systems bolt on later, like tracking tags or session IDs. Whatever variant of the URL gets shared, the tag keeps pointing consolidation at the clean version.