So yes, the meta viewport tag should be used on all websites and is mandatory if you want a good user experience. You may also need to use media queries to change CSS for different screen widths, like collapsing a menubar into a hamburger menu.

Why is a viewport needed?

A viewport makes sure a site display well on all device (mobile phones, tablets, computers, and even larger screens). In a nutshell, viewport plays a significant role in designing responsive and mobile-friendly websites.

Is it bad to use VW CSS?

2 Answers. vw and vh are standard units and should work like any other unit. Even if they are used unusually, as long as they are used validly, it is fine to use them like all other units.