Question

How can I set my viewport on my desktop (while developing my app) to the iPhone screen size, without touching the CSS?

I’m developing my app with jQueryMobile.

Answer 1

The old-fashioned definition of the viewport (before scaling and the viewport meta tag became common with the iPhone) is just the size of the html element. So you can just style it as follows:

html {
    position: absolute;
    width: 320px;
    height: 480px;
}

Alternatively, use a browser extension (like the “Web Developer Toolbar” for Firefox to resize your browser window to the size you want your viewport to have.