After the update of April 21, 2015, known as Mobilegeddon, many companies have been looking to their websites differently. Having a mobile version is no longer superfluous and has become vital for those who want to succeed on the Internet.
But there are many ways to make a website able to appear in the results of mobile search and one of them, perhaps the most common, is to create a subdomain that will be shown to the user when accessing a particular page via mobile.
It is common to have the m.site.com.br nomenclature, indicating that this is a specific domain for mobile devices. This format allows a lot of freedom to create an interface, since it does not depend on desktop interface to work. But you must be careful about the content of notes equivalent between versions. Only redirection may not work for the engine to index page versions properly, so Google indicates some tags with which this control can be done more effectively.
INDEXING CONTROL TAGS ON GOOGLE MOBILE
To indicate what is the mobile version of a page within the subdomain “m.” you must configure two tags: one in the desktop version of the page and another in the mobile version. A practical example makes it easy to understand that implementation:
The page site.com/pag1 has as compatible page in the mobile version the address m.site.com/pag1.
To indicate to Google that one supports the other the following implementation should be made:
On page site.com/pag1 the following tag must be added to the header (<head>) of the page:
<link rel=”alternate” media=”only screen and (max-width: 640px)” href=” m.site.com/pag1″ >
This tag will indicate the Google robot that the version for devices with resolution up to 640px of width is the m.site.com.
Now, in the mobile version page, a canonical tag should be included indicating the page with its contents on the desktop.
<link rel=”canonical” href=”http://site.com/pag1″ >
Each of the website pages will need to have implemented one of the tags, each according to their respective version.