URL Canonicalization Checker (WWW, Non-WWW, HTTPS)
Check that www, non-www, http and https versions of your site redirect to one URL. Free URL canonicalization checker to avoid duplicate content.
About URL Canonicalization Checker
The Canonical URL Checker analyzes webpage source code and HTTP headers to detect and inspect rel="canonical" tags. It verifies whether a page defines a self-referencing canonical or points search engine crawlers toward an alternate preferred URL, helping you monitor indexing directives.
Designed for technical SEO specialists, web developers, and site owners, this browser-based utility runs on your device without software downloads or account signups. Use it to diagnose duplicate content warnings, validate URL parameters, and confirm your canonical configurations are error-free.
Key features
- Extracts rel=canonical link elements from page HTML
- Identifies HTTP response header canonical implementations
- Verifies self-referencing versus cross-domain canonical URLs
- Flags mismatched protocols between HTTP and HTTPS links
- Highlights relative URLs that should be absolute paths
- Runs entirely in your browser with zero configuration
How to use URL Canonicalization Checker
- Enter the complete webpage URL you want to analyze.
- Click the check button to retrieve and process the page tags.
- Review the declared canonical address alongside the requested URL.
- Confirm whether the canonical directive points to your intended destination.
- Update your source code or server headers if discrepancies appear.
Who is it for?
- E-commerce stores auditing faceted navigation and product variant pages.
- SEO professionals conducting technical site audits for clients.
- Web developers validating canonical redirects during site migrations.
- Content syndicators ensuring republishing partners credit original sources.
- Marketing teams confirming UTM tracking parameters do not dilute page authority.
Frequently asked questions
What is a canonical URL?
A canonical URL is an HTML link element with the rel="canonical" attribute that tells search engines which version of a page represents the master copy. It prevents duplicate content issues by consolidating ranking signals to one preferred address.
Why is URL canonicalization important for SEO?
Canonicalization prevents search engines from indexing multiple versions of identical or similar content, such as URLs with tracking parameters or different sorting filters. It ensures page authority and link equity are assigned to the primary page you want to rank.
What happens if a page has multiple canonical tags?
If a page declares more than one rel="canonical" tag in the HTML or HTTP headers, search engines like Google will typically ignore all of them. This can lead to unexpected URL indexing and split ranking signals.
Can a canonical tag point to a different domain?
Yes. Cross-domain canonical tags are valid and frequently used when syndicating content across multiple websites, allowing the publishing platform to pass credit back to the original source.
Is this canonical URL checker free to use?
Yes. The tool is free to use directly in your browser without requiring an account or subscription.