What is the canonical tag?
Canonical tag has been rolled out to tackle
duplicate content issues, but it may be slightly
• It can be used in many “creative” ways
• It has the potential to break your site
It’s very easy to implement and it looks to work
quite well for URL like:
• Faceted / sorted searches
• Tracking parameters / Session ID
• Duplicate content across categories navigation
• Useful for circumstance where 301 is not easy to
be implemented (e.g. affiliate links)
• It has been allegedly said to consolidate the link
juice / popularity
• It’s not a replacement for fundamental URL
• It may fall down with contradictory
• It’s still an hint and not a directive, hence it’s up
to Search Engine stick on it
A (bad) implementation example
The code suggests the canonical URL of the Drupal node setup as the home
page as the URL to be indexed, but…
The suggested URL do a redirects
Thus making the previous canonical useless.
To canonicalize or to not canonicalize?
Google stated “there is not a problem to use the
canonical tag on every pages of your site”.
On the other side, Bing says “using it everywhere
(as a placeholder) is essentially telling us the page
to be a copy of itself”.
What a dilemma!
Best practices to comply with all SEs
Canonical tag implementation should not be seen in
isolation as multiple factors contribute to site’s visibility.
As general principles, use a canonical tag bearing in
- Redundant code make pages loading slower
- Canonical is not an excuse to ignore URL best practice
- Use the 301 redirect every time it is possible
- Consistently links pages
- Canonical tag not to point to Error pages