# Canonical URL Checker

> Check a page's canonical tag against its final URL. Catches multiple or relative canonicals, http vs https, cross-domain targets and Link header conflicts.

Use it free at https://swipetolaunch.com/tools/canonical-url-checker

## How to use it

1. **Paste a URL.** Try the exact URL people land on, including variants with parameters or www.
2. **Check canonical.** We follow redirects, read canonical tags in the HTML and in the HTTP Link header, and test the target URL.
3. **Read the verdict.** Self-referencing, pointing elsewhere, missing or conflicting, with what to change.

## What a canonical tag does

When the same content is reachable at several URLs, such as with and without www, with tracking parameters, or sorted differently, search engines have to choose one to index. `<link rel="canonical" href="…">` tells them which one you prefer. Ranking signals from the duplicates are then consolidated onto that URL.

It is a strong hint, not a command. Google may pick a different canonical if your signals disagree, for example if the canonical points at a page that redirects, or if internal links and the sitemap all use another version.

## What this checker tests

- **Present or missing.** Without a canonical, Google picks one for you.
- **Self-referencing.** The most common correct setup: each page names itself. Small differences like a trailing slash are tolerated.
- **Pointing elsewhere.** Correct for real duplicates, such as a printer view or a filtered product list. A mistake on a page you want ranked, and one of the quieter ways to lose a page from search.
- **Multiple canonicals.** Two different canonicals, often from a theme and a plugin, make Google ignore both.
- **Relative URLs.** `href="/pricing"` works in theory but breaks easily. Use absolute URLs.
- **http vs https and www.** A canonical on http:// for an https page, or on the other www variant, sends mixed signals.
- **Cross-domain.** Legitimate for syndicated articles, harmful by accident.
- **Link header.** Canonicals can also be sent as an HTTP header, which is how PDFs declare them. The checker reads both and flags disagreement.
- **The target itself.** We request the canonical URL and warn if it redirects or returns an error.

## Canonicals and redirects

If a URL should never be visited, a 301 redirect is stronger than a canonical. Use canonicals for duplicates that need to stay reachable. The [redirect checker](/tools/redirect-checker) shows a full redirect chain, and the [SEO checker](/tools/seo-checker) puts the canonical in context with the rest of the page.

## What you get

- Compares canonical with the final URL after redirects
- Reads HTML tags and the HTTP Link header
- Flags multiple, relative, http and cross-domain canonicals
- Requests the canonical target to confirm it answers 200

## Questions

### Should every page have a self-referencing canonical?

It is good practice. A self-referencing canonical protects against duplicates created by tracking parameters, session IDs and other URL variations you do not control.

### What happens if a page has two canonical tags?

If they point at different URLs, Google ignores both and picks a canonical itself. Remove one, usually by turning off the duplicate output in your theme or SEO plugin.

### Can a canonical point to another domain?

Yes. Cross-domain canonicals are used for syndicated content, so the original publisher gets the credit. If you did not intend it, it hands your page's ranking to the other site.

### Is a canonical the same as a 301 redirect?

No. A redirect sends visitors and crawlers to the new URL. A canonical keeps the page reachable but asks search engines to index another URL. Use a redirect when the old URL should not be used at all.