html META TAGs
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
The initial-scale property controls the amplification level when the page is loaded for the first time. Maximum-scale, minimum-scale, and user-scalable properties control the permission for the user to increase or decrease the page.
width
Defines a width for the viewport. The values can be in PX or "device-width", which automatically determines a value equal to the screen width of the device. Example:
<meta name="viewport" content="width=320px">
height
Sets a height for the viewport. The values can be in PX or "device-height", which automatically determines a value equal to the height of the screen of the device. Example:
<meta name="viewport" content="height=device-height">
initial-scale
Sets the initial viewport scale.
user-scalable
Defines the possibility of the user zooming in on a certain place on the screen. It is activated when the user double-taps on a place on the screen.
Source : Tableless