How to make page width equal to screen width in Opera Mobile, iOS, Android etc

Question

Such browsers as Opera Mobile, iOS browser, Android browser (last two use webkit engine) emulate lager device's screen, than it is. For example: real device's screen width is 480px, but Opera Mobile shows the page, like the screen is 850px width.

How i can prevent such browsers from emulating larger device's screen size, and make them to display web page as wide, as real device's screen?

Answer 1

<meta name="viewport" content="width=device-width;" /> in the head should set the viewport to the device width

Answer 2

Use <meta name="viewport" />