The rel=”canonical” link attribute, also known as a “canonical tag”, is a way for webmasters to indicate to search engines which version of a page is the preferred or “canonical” version. It helps to resolve duplicate content issues on a website.
Here’s how it works:
- When there are multiple pages with similar or identical content, the webmaster can use the rel=”canonical” link in the head of the HTML code of the non-preferred pages, pointing to the preferred (canonical) page.
- Search engines, such as Google, will treat the preferred page as the authoritative version and will index it accordingly.
- The rel=”canonical” link on the non-preferred pages informs search engines that these pages should not be indexed, as they are duplicates of the preferred page.
Example:
Let’s say you have two pages with similar content:
You want www.example.com/page1 to be the preferred (canonical) page. To indicate this to search engines, you would add the following code to the head of the HTML code of www.example.com/page2:
<link rel="canonical" href="http://www.example.com/page1">
This tells search engines that the preferred (canonical) version of the content is located at www.example.com/page1.
It’s important to note that using the rel=”canonical” tag is just a suggestion to search engines, and they may still choose to index the non-preferred pages in certain cases. However, using the canonical tag correctly and consistently can help to reduce duplicate content issues and improve the efficiency of the search engines’ crawling and indexing process.
Additionally, the rel=”canonical” tag can also be used across different websites. For example, if you have the same content on multiple websites, you can use the canonical tag on the non-preferred pages to indicate which version of the content is the preferred one.