Canonical Tag Checker
Verify and audit canonical URL tags. Detect duplicate tags, secure link configurations, and self-referencing issues.
Page Source Check
Paste your page's HTML output to scan its canonical definition.
What is a Canonical Tag?
A canonical tag (`rel="canonical"`) is an HTML element in the header of a web page that tells search engines which URL is the master or preferred copy of the page.
Adding canonical tags prevents duplicate content issues by consolidation indexing signals onto a single authoritative link.
Best Practices:
1. Single tag: Do not include multiple canonical tags on one page.
2. Absolute URLs: Always use complete absolute paths including HTTPS protocols.
3. Symmetrical targets: Ensure target pages match sitemaps and index setups.