Canonical URL

Introduction

Canonical URL Tag is part of the HTML header on a web page.

i<link rel="canonical" href="http://www.seopedia.wikidot.com/" />

This tag will tell search engines that the page should be treated as though it were a copy of the url www.seopedia.wikidot.com and that all of the link & content metrics the engines apply should technically flow back to that URL.

Differences with 301 redirect

  • 301 redirect re-points all traffic (bots and visitors) whereas the canonical URL tag is only for search engines.
  • 301 redirect is a much stronger signal that multiple pages have a single, canonical source.
  • 301 redirect carry cross-domain functionality.

When you should use the canonical tag

The canonical tag should be applied when the category url system creates multiple versions of the same page.
Example:
www.seopedia.wikidot.com
http://www.seopedia.wikidot.com
http://www.seopedia.wikidot.com/index.php
http://www.seopedia.wikidot.com/index.php?color=black