Produce a canonical link tag and check the URL for the mistakes that break it.
The absolute URL that should be treated as the original version
Checks
A canonical is a strong hint, not a command — search engines may disregard one that conflicts with other signals. Use exactly one per page, place it in <head>, and prefer a redirect when the alternative URL should stop being reachable at all.
A self-referencing canonical
The usual case
https://example.com/pageConsolidating parameters
Point the filtered URL at the clean one
https://example.com/shopA URL with a fragment
Flagged — fragments are ignored
https://example.com/page#topThe absolute URL you want treated as the original.
Protocol, fragments and query strings are each explained.
One canonical tag per page, inside <head>.
A relative canonical is a hint search engines may resolve differently than you expect. The tool treats it as an error, because it usually is one.
Every finding says why it matters — a fragment being ignored, an http canonical undermining an https site — so the fix is obvious.
Whether to keep parameters is a judgement call, so it is raised as a question rather than decided for you.
Generate a rel="canonical" link and validate the URL before you use it. Canonicals are how you tell search engines which of several similar URLs is the real one — the version with tracking parameters, the one with a trailing slash, the printable copy. The rules are unforgiving in specific ways: the href must be absolute, a fragment is ignored, and pointing at http when the site serves https undermines the whole point. Each of those is checked, with the reason explained rather than just flagged.
Keep going
Related pages in SEO Tools, plus what others are using right now.
More seo tools that pair well with this one.
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See an approximation of how your title, URL and description may appear in results.
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Count characters with and without spaces, against the limits that matter.
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Sample and population standard deviation and variance, both shown, with the working.
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Check a downloaded file against its published checksum, without uploading anything.
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