SEO
Canonical Tag
Quick definition
A canonical tag (<link rel='canonical'>) tells search engines which version of a page is the preferred, indexable URL when duplicate or near-duplicate versions exist.
Canonical tags resolve duplicate-content issues caused by URL parameters, session IDs, http/https variants, www/non-www, tracking links, and pagination.
Why Canonical Tag matters
Without canonicals, duplicate pages can split link equity, dilute rankings, and waste crawl budget. With them, you tell Google exactly which URL to consolidate signals on.
How Canonical Tag works in practice
Each page should self-canonicalize to its own clean URL. Use cross-domain canonicals carefully when syndicating content to ensure your version remains the indexed one.
Best practices
- Every page should specify a canonical URL.
- Use absolute URLs (https://...), not relative paths.
- Always self-canonicalize unless intentionally consolidating.
- Audit canonicals after every URL or template change.