How can I scale an entire web page with CSS?

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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%?)

resize css html
12 Answers
Jon_Galloway_50

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.

user_730700

I have the following code that scales the entire page through CSS properties. The important thing is to set body.style.width to the inverse of the zoom to avoid horizontal scrolling. You must also set transform-origin to top left to keep the top left of the document at the top left of the window.

        var zoom = 1;
        var width = 100;

        function bigger() {
            zoom = zoom + 0.1;
            width = 100 / zoom;
            document.body.style.transformOrigin = "left top";
            document.body.style.transform = "scale(" + zoom + ")";
            document.body.style.width = width + "%";
        }
        function smaller() {
            zoom = zoom - 0.1;
            width = 100 / zoom;
            document.body.style.transformOrigin = "left top";
            document.body.style.transform = "scale(" + zoom + ")";
            document.body.style.width = width + "%";
        }
user_27132500

Scale is not the best option

It will need some other adjustments, like margins paddings etc ..

but the right option is

zoom: 75%
user_35340150

As Johannes says -- not enough rep to comment directly on his answer -- you can indeed do this as long as all elements' "dimensions are specified as a multiple of the font's size. Meaning, everything where you used %, em or ex units". Although I think % are based on containing element, not font-size.

And you wouldn't normally use these relative units for images, given they are composed of pixels, but there's a trick which makes this a lot more practical.

If you define body{font-size: 62.5%}; then 1em will be equivalent to 10px. As far as I know this works across all main browsers.

Then you can specify your (e.g.) 100px square images with width: 10em; height: 10em; and assuming Firefox's scaling is set to default, the images will be their natural size.

Make body{font-size: 125%}; and everything - including images - wil be double original size.

user_845960

For Cross-Browser Compatibility :

Example Goes Below :

<html><body class="entire-webpage"></body></html>



.entire-webpage{
        zoom: 2;
        -moz-transform: scale(2);/* Firefox Property */
        -moz-transform-origin: 0 0;
        -o-transform: scale(2);/* Opera Property */
        -o-transform-origin: 0 0;
        -webkit-transform: scale(2);/* Safari Property */
        -webkit-transform-origin: 0 0;
        transform: scale(2); /* Standard Property */
        transform-origin: 0 0;  /* Standard Property */
    }
user_99952340 
 * {
transform: scale(1.1, 1.1)
}

this will transform every element on the page

user_105953050

Jon Tan has done this with his site - http://jontangerine.com/ Everything including images has been declared in ems. Everything. This is how the desired effect is achieved. Text zoom and screen zoom yield almost the exact same result.

user_172520

CSS will not be able to zoom on demand, but if you couple CSS with JS, you could change some values to make a page look bigger. However, as it has been said, this feature is standard nowadays in modern browsers: no need to replicate it. As a matter of fact, replicating it will slow down your website (more things to load, more JS or CSS to parse or execute and apply, etc.)

user_1420200

you have to set the zoom property in style. Now interesting part is how to calculate it. This is what I did.

let zoom = Number((window.innerWidth / window.screen.width).toFixed(3));
document.firstElementChild.style.zoom = zoom;

this will calculate the ratio of current window width to actual device width. Then set that value to top level html element zoom property. Top level html element can be accessed using document.firstElementChild

You can put this code inside window.onresize function to make the whole page zoom accordingly.

set the height of main wrapper div to 100% to prevent white space on zoom.

user_32697090
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