Free SEO Tool
Canonical URL generator
Normalise your URLs and generate the correct rel="canonical" tag in seconds. Paste a URL, configure your preferences for protocol, www, trailing slashes and more, then compare variants to catch duplicate content issues before they hurt your rankings.
Enter the URL you want to generate a canonical tag for.
Add duplicate or alternate versions of the URL to check whether they resolve to the same canonical.
Normalisation Preferences
Upgrade http:// to https://
Add www prefix to the hostname
Strip trailing / from paths
Strip all ?key=value pairs
Convert URL path to lowercase
Strip :80 (HTTP) and :443 (HTTPS)
Strip #anchor from URLs
Strip /index.html, /index.php, etc.
What are canonical URLs?
Canonical URLs tell search engines which version of a page is the “primary” one when multiple URLs serve the same or very similar content. Getting them right is fundamental to a clean, crawlable site.
The duplicate content problem
Search engines can access the same page through many different URLs. A single product page, for example, might be reachable via HTTP and HTTPS, with or without www, with a trailing slash, with tracking parameters, or through an index file path. To Google, each of those is a separate URL — and if you don’t specify which one is authoritative, the search engine has to guess. That dilutes link equity, wastes crawl budget, and can suppress your rankings.
Example — five URLs, one page:
- http://example.com/products/shoes
- https://example.com/products/shoes
- https://www.example.com/products/shoes
- https://www.example.com/products/shoes/
- https://www.example.com/products/shoes?ref=nav
How rel="canonical" works
The <link rel="canonical"> tag is placed in the <head> of every page that might have duplicate variants. It points search engines to the single preferred URL that should receive all ranking signals. You can also send it as an HTTP response header, which is useful for non-HTML resources like PDFs.
- Consolidates link equity from all duplicate URLs onto the canonical version.
- Prevents crawl budget waste by guiding Googlebot to the right page.
- Avoids “duplicate content” flags in search console and third-party audits.
- Works alongside 301 redirects and sitemap URLs for a belt-and-braces approach.
Common canonical issues
Most canonical problems are surprisingly simple to cause and easy to overlook. The generator above helps you normalise URLs consistently, but here are the issues to watch for across your site:
Protocol mismatch
HTTP and HTTPS versions both being indexed. Always canonical to HTTPS and redirect HTTP.
www vs non-www
Both variants accessible without a redirect or consistent canonical tag pointing to one version.
Trailing slash inconsistency
/page and /page/ both returning 200. Pick one convention and enforce it with redirects.
Query parameter pollution
UTM tags, session IDs, sort parameters and filters creating thousands of indexable duplicate URLs.
Index file paths
/index.html and /index.php serving the same content as the directory root.
Case sensitivity
/About-Us and /about-us treated as separate pages. Always lowercase paths and redirect uppercase variants.
Best practice
Use self-referencing canonicals on every page, not just pages with known duplicates. This protects you against future duplication from query parameters, syndication, or content scrapers. Combine with 301 redirects for non-canonical variants and include only canonical URLs in your XML sitemap.
Need help resolving canonical issues?
Canonical tags are just one piece of the technical SEO puzzle. Our specialists can audit your entire site for duplicate content, crawl issues, and indexation problems — then fix them for you.