Best Practices & Why This Matters
A canonical tag tells search engines which version of a webpage is the "primary" or preferred version.
This prevents issues caused by duplicate or near-duplicate content, ensuring ranking signals aren’t split
between multiple URLs.
- Single Canonical Tag: Using multiple canonicals can confuse crawlers, so stick to one per page.
- Match Domain Intent: If you intentionally point canonicals to a different domain (e.g., a syndicated version or main site), ensure it’s done carefully to avoid traffic leaks.
- Check for 2xx: Canonical URLs should be valid, returning a 200 (or other 2xx) status code. A 404 or 5xx code can undermine your SEO efforts.
- Absolute URLs: Relative canonical URLs can cause confusion for search engines, so using absolute URLs is typically recommended.
How to Use:
- Enter the full URL of the page you want to check (e.g.
https://www.example.com/article).
- Click “Check Canonical Tag.” The tool will fetch the page’s HTML, parse out
<link rel="canonical">, and display each link found (usually there should be only one).
- Review the status code, ensuring it's 2xx and that no errors occurred. If the canonical domain differs from the input URL, verify that’s intentional.
- Implement corrections if you see multiple canonical tags or if your canonical URL is broken or returning a non-2xx code.
Example: If your canonical says https://example.com/main-article but returns a
404 or 500, search engines may ignore it or penalize you, resulting in lost
ranking signals. Fixing the canonical or removing the invalid tag can help unify page signals.