viewport

MetaExtension viewport

Is used to give the browser instructions on how to control the page's scaling and dimensions.

Attention: Is essential for the use of media-queries in css!

Usage

<meta name="viewport" content="width=device-width, initial-scale=1.0">

content may be:

Read more at W3Schools.

W3

In the WHATWG Wiki

Up to date: v2.3.3