How to get browser width using JavaScript code?

user_20126 0
Viewed 311891

I am trying to write a JavaScript function to get the current browser width.

I found this one:

console.log(document.body.offsetWidth);

But its problem that it fail if the body has width 100%.

Is there any other better function or a workaround?

css html javascript
9 Answers

It's a pain in the ass. I recommend skipping the nonsense and using jQuery, which lets you just do $(window).width().

user_475290

Update for 2017

My original answer was written in 2009. While it still works, I'd like to update it for 2017. Browsers can still behave differently. I trust the jQuery team to do a great job at maintaining cross-browser consistency. However, it's not necessary to include the entire library. In the jQuery source, the relevant portion is found on line 37 of dimensions.js. Here it is extracted and modified to work standalone:

function getWidth() {
  return Math.max(
    document.body.scrollWidth,
    document.documentElement.scrollWidth,
    document.body.offsetWidth,
    document.documentElement.offsetWidth,
    document.documentElement.clientWidth
  );
}

function getHeight() {
  return Math.max(
    document.body.scrollHeight,
    document.documentElement.scrollHeight,
    document.body.offsetHeight,
    document.documentElement.offsetHeight,
    document.documentElement.clientHeight
  );
}

console.log('Width:  ' +  getWidth() );
console.log('Height: ' + getHeight() );

Original Answer

Since all browsers behave differently, you'll need to test for values first, and then use the correct one. Here's a function that does this for you:

function getWidth() {
  if (self.innerWidth) {
    return self.innerWidth;
  }

  if (document.documentElement && document.documentElement.clientWidth) {
    return document.documentElement.clientWidth;
  }

  if (document.body) {
    return document.body.clientWidth;
  }
}

and similarly for height:

function getHeight() {
  if (self.innerHeight) {
    return self.innerHeight;
  }

  if (document.documentElement && document.documentElement.clientHeight) {
    return document.documentElement.clientHeight;
  }

  if (document.body) {
    return document.body.clientHeight;
  }
}

Call both of these in your scripts using getWidth() or getHeight(). If none of the browser's native properties are defined, it will return undefined.

T_Pops_3073380

An important addition to Travis' answer; you need to put the getWidth() up in your document body to make sure that the scrollbar width is counted, else scrollbar width of the browser subtracted from getWidth(). What i did ;

<body>
<script>
function getWidth(){
return Math.max(document.body.scrollWidth,
document.documentElement.scrollWidth,
document.body.offsetWidth,
document.documentElement.offsetWidth,
document.documentElement.clientWidth);
}
var aWidth=getWidth();
</script>
</body>

and call aWidth variable anywhere afterwards.

user_66293380

An adapted solution to modern JS of Travis' answer:

const getPageWidth = () => {
  const bodyMax = document.body
    ? Math.max(document.body.scrollWidth, document.body.offsetWidth)
    : 0;

  const docElementMax = document.documentElement
    ? Math.max(
        document.documentElement.scrollWidth,
        document.documentElement.offsetWidth,
        document.documentElement.clientWidth
      )
    : 0;

  return Math.max(bodyMax, docElementMax);
};
user_6128470 

function getWidth() {
  return Math.max(
    document.body.scrollWidth,
    document.documentElement.scrollWidth,
    document.body.offsetWidth,
    document.documentElement.offsetWidth,
    document.documentElement.clientWidth
  );
}

function getHeight() {
  return Math.max(
    document.body.scrollHeight,
    document.documentElement.scrollHeight,
    document.body.offsetHeight,
    document.documentElement.offsetHeight,
    document.documentElement.clientHeight
  );
}

console.log('Width:  ' +  getWidth() );
console.log('Height: ' + getHeight() );

user_168560490
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