Redirect Map Generator
Map old URLs to new ones free and export a normalized redirect CSV plus Vercel redirects JSON. Validates ev...
Open toolFree technical SEO utility
Canonical URL Checker
Compare a page's public URL with the canonical URL found in its HTML source. Check protocol, host, path, query and fragment formatting.
View the page HTML and copy the href from its rel="canonical" link. This tool does not fetch the URL.
Ready to check
Enter both URLs, then run the check.
Values are compared in your browser and are not sent to a server.
How to use the Canonical URL Checker
- Open the page's HTML source in your browser and copy the href from its rel='canonical' link tag.
- Paste the page's public URL into the 'Page URL' field and the copied href into the 'Canonical URL' field, or click 'Load sample' to try it.
- Click 'Check canonical' to compare protocol, host, path, query parameters and fragments.
- Review the ok and warning items, such as a canonical pointing to a different host or containing a fragment.
Why it matters
Canonical tags tell search engines which URL is the preferred version when duplicate or near-duplicate pages exist. A wrong canonical can consolidate ranking signals onto the wrong page, waste crawl budget on parameter URLs, or quietly tell Google to ignore your best content. Checking the tag before publishing is a small technical-SEO habit that prevents large indexing problems, especially on faceted ecommerce and paginated sites.
Canonical URL Checker FAQs
Does this tool read the canonical tag from my page automatically?
No. Paste the canonical href from your page source yourself, because browser cross-origin restrictions prevent this server-free page from reliably fetching arbitrary websites. Copy the value from view-source and the tool compares it against the page URL entirely in your browser.
Should canonical URLs include tracking parameters?
Usually not. Canonical links should point to the preferred clean URL, so remove tracking parameters like utm_source when they do not define a distinct page. The tool's comparison normalizes common tracking parameters before judging whether the URLs match. Keep the canonical clean and let parameters live only in the URLs users actually visit.
What does a different-host warning mean?
It means the canonical points to another domain, which is valid for intentional cross-domain canonicals, such as syndicated content crediting the original publisher. If you did not intend that, it is likely a copy-paste error worth fixing. When the cross-domain link is deliberate, leave it alone; it is a supported SEO pattern.
Why do fragments in canonical URLs matter?
Fragments like #section never reach the server and do not define a distinct page, so they should not appear in a canonical URL. A canonical with a fragment looks sloppy to search engines and can confuse duplicate-content handling, so the checker flags it for removal.