Free SEO tool
Canonical URL Checker
Paste a list of URLs to detect canonical issues like trailing slashes, protocol mismatches, www vs non-www, uppercase paths, and duplicate query parameters.
URL Input
Canonical Best Practices
Self-referencing canonicals
Every page should have a canonical tag pointing to itself. This signals to search engines which version of the URL is authoritative, even if no duplicates exist yet.
Pick one protocol and stick to it
Choose HTTPS (non-negotiable in 2026) and set up 301 redirects from HTTP. Serving the same content on both protocols splits link equity and confuses crawlers.
www vs non-www consistency
Pick one domain variant (www or bare domain) and redirect the other with a 301. Set your preferred domain in Google Search Console. Mixing both creates duplicate content.
Trailing slash discipline
Choose a trailing slash convention for your CMS and enforce it site-wide. Most static site generators (Eleventy, Next.js) default to trailing slash. Configure your server to 301 redirect the non-canonical variant.
Query parameters and canonical tags
Tracking parameters (?utm_source, ?ref, ?fbclid) create duplicate URLs. Use canonical tags to point all parameter variants back to the clean URL without the query string.