Using the viewport meta tag the wrong way can hinder users with visual problems accessing your website. By setting
maximum-scale=1.0, you are disabling the functionality to use pinch zoom on mobile devices, and forcing users to view your page a certain way.
The bad way:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0">
The good way:
<meta name="viewport" content="width=device-width, initial-scale=1.0">
maximum-scale=1.0 allows your site to meet users’ needs and provide a better experience.
user-scalable attribute can likewise cause problems for users who use the built-in zoom functionality of their web browser. The attribute is set as
user-scalable=yes by default, which means that users are able to control the zoom setting on a webpage. Changing it to
user-scalable=no would prevent desktop users’ zoom settings from applying to a webpage and prevent mobile users from using pinch zoom.
no to assure better accessibility of your site; either leave it as defaulted by not referencing the
user-scalable attribute or set it to