The Canonical Tag ( rel=canonical element) often called the “canonical link”. It is an HTML element that helps Search Engines prevent duplicate content issues by specifying the “canonical URL”, the “preferred” version of a web page. Actually we give Canonical tag just for search engines not for users. It also help. in Search engine Optimization of Web pages.
How to Use the Canonical Tag?
In canonical link we give URL of preferred Web Page or Master page .This tag is present in HTML header portion where meta Title and meta Description tags are present. For Canonical Tag following Syntax is Used:
<link rel=”canonical” href=”http://www.domain.com/your-preferred-url/” />
HOW the rel=canonical tag Help in SEO?
It tells search engine/Webmasters that one URL is equivalent to another URL (preferred Page URL) where search results are related to this page. The main use of this tag is to avoid issues related to duplicate content on your website which generally occurs due to similar URL parameters or the existence of similar content. The canonical tag was introduced to handle duplicate content for web masters who have similar or identical content within their blog.There are many legitimate reasons for duplicate content, specially system generated URLs. These include:
- Multiple URLs – are generated in eCommerce websites where different URLs are created through different filter options for price, color, rating, etc.
- Session ID URLs – These session ID URLs are automatically generated. The same applies to tracking URLs, breadcrumb links, printer friendly versions, and permalinks in certain CMS.
- Case – users, and most browsers are case insensitive and. It is not necessarily true for search engines, so if your website mixes up case in filenames and folder structure, you need to use the canonical tag.
- Mobile URL – Special URL (typically m.mydomain.com) for the mobile version of your website then you need to use Canonical tag for master page.
- Country URL – when using multiple country specific URLs, the content largely remains the same, with only a few minor differences.
- HTTP, HTTPS & WWW – search engines see http://www.domain.com, http://domain.com and https://www.domain.com as distinct pages, and will crawl (and possibly index) them as separate URLS.
When To Use Canonical?
- When search engine is confused about which URL of the page should be preferred and indexed.
- Search engine is confused about what to do with Link Metrics (Authority, Anchor text, Link juice)whether to direct to one page or to distribute in different versions.
- Search Engine don’t know which page to rank for query result.
Written by: Punam Kashyap