Canonical URL Checker

The Canonical URL Checker is a free online tool that turns any messy URL into the clean canonical form search engines expect — and generates the exact <link rel="canonical"> tag to paste into your page's <head>. When the same content is reachable through several URLs (http vs https, www vs non-www, trailing slashes, tracking parameters like utm_source or fbclid, query strings in different orders), Google sees near-duplicate pages and splits the ranking signals between them. A canonical tag is the standard way to tell Google which version is the master: point every duplicate at one URL and all the authority consolidates there instead of leaking away. This canonical checker normalizes your URL step by step — host lowercased, default ports removed, tracking parameters stripped, query parameters sorted, fragments and trailing slashes dropped — then shows you exactly what changed and outputs a ready-to-copy canonical tag. Every check runs entirely in your browser, so the URLs you enter never touch a server.

1. 1

   Paste the URL you want to canonicalize into the input field — include the full scheme (https://) or the tool will flag it as invalid.

2. 2

   Click "Canonicalize". The tool normalizes the URL and shows a diff: everything that changed (case, ports, parameters, fragment, trailing slash).

3. 3

   Review the normalized URL — it should be the exact version you want Google to index (right host, right protocol, right path).

4. 4

   Copy the generated <link rel="canonical" href="…" /> tag from the output panel.

5. 5

   Paste the tag into the <head> of your page. Repeat for each template on your site — every page should declare exactly one canonical.

• Tracking-parameter duplicates — strip utm_source, gclid, fbclid and friends so shared links don't create duplicate pages.
• CMS audits — check canonical URL your templates (WordPress, Shopify, Next.js) will emit for a product or post.
• E-commerce filters — canonicalize /item/123/?sort=price back to the base /item/123/ page.
• Trailing-slash consistency — resolve the /blog/post/ vs /blog/post split on one canonical URL.
• Syndicated content — generate the tag that points a syndicated copy back to your original article.
• Print and AMP versions — declare the main page as the canonical target of its alternate variants.

• Every page should declare exactly one canonical tag — ideally self-referential (pointing at itself) so each URL stands on its own.
• Use absolute URLs (https://www.example.com/page), never relative ones — relative canonicals are ignored by most crawlers.
• The canonical URL must return 200: a canonical pointing at a 404 or a redirecting URL is a common, silent mistake.
• Never chain canonicals: if page A canonicals to B and B canonicals to C, Google may stop at the first hop — point A directly at C.
• Only one canonical declaration per page. If multiple tags are present, Google will generally pick one and ignore the rest — but you should never rely on that.
• Don't mix noindex with canonical: a page that says "don't index me" AND "my master is X" sends contradictory signals. If the page shouldn't exist, use a 301 instead.

• Check canonical tags after every theme, plugin, or framework update — the most common source of duplicate tags is a second tag injected by a new component.
• A canonical is a hint, not a directive — Google can ignore it if the pages are materially different.
• If a canonical URL 404s or redirects, Google may drop the page from the index. Test the URL you canonicalize to.
• For duplicates that shouldn't exist at all, prefer a 301 redirect over a canonical tag — it is stronger and consolidates users too.