How can I scale an entire web page with CSS?

Using Firefox, you can enlarge an entire web page by simply pressing CTRL +. What this does is proportionally enlarge the entire web page (fonts, images, etc).

How can I replicate the same functionality using simply CSS?

Is there something like page-size: 150% (which would increase the entire page portions by x%?)

Solution 1:

You might be able to use the CSS zoom property - supported in IE 5.5+, Opera, and Safari 4, and Chrome

Can I use: css Zoom

Firefox is the only major browser that does not support Zoom (bugzilla item here) but you could use the "proprietary" -moz-transform property in Firefox 3.5.

So you could use:

div.zoomed { 
    zoom: 3; 
    -moz-transform: scale(3); 
    -moz-transform-origin: 0 0;
} 

Solution 2:

This is a rather late answer, but you can use

body {
   transform: scale(1.1);
   transform-origin: 0 0;
   // add prefixed versions too.
}

to zoom the page by 110%. Although the zoom style is there, Firefox still does not support it sadly.

Also, this is slightly different than your zoom. The css transform works like an image zoom, so it will enlarge your page but not cause reflow, etc.

Edit updated the transform origin.

Solution 3:

If your CSS is constructed completely around ex or em units, then this might be possible and feasible. You'd just need to declare font-size: 150% in your style for body or html. This should cause every other lengths to scale proportionally. You can't scale images this way, though, unless they get a style too.

But that's a very big if on most sites, anyway.