make iframe height dynamic based on content inside- JQUERY/Javascript

make iframe height dynamic based on content inside- JQUERY/Javascript

I am loading an aspx web page in an iframe. The content in the Iframe can be of more height than the iframe’s height. The iframe should not have scroll bars.
I have a wrapper div tag inside the iframe which basically is all the content. I wrote some jQuery to make the resize happen :
$(“#TB_window”, window.parent.document).height($(“body”).height() + 50);

TB_window is the div in which the Iframe is contained.
body – the body tag of the aspx in the iframe.
This script is attached to the iframe content. I am getting the TB_window element from the parent page. While this works fine on Chrome, but the TB_window collapses in Firefox. I am really confused/lost on why that happens.


Solution 1:

You can retrieve the height of the IFRAME‘s content by using:

After the IFRAME is loaded, you can then change the height by doing the following:

<script type="text/javascript">
  function iframeLoaded() {
      var iFrameID = document.getElementById('idIframe');
      if(iFrameID) {
            // here you can make the height, I delete it first, then I make it again
            iFrameID.height = "";
            iFrameID.height = iFrameID.contentWindow.document.body.scrollHeight + "px";

Then, on the IFRAME tag, you hook up the handler like this:

<iframe id="idIframe" onload="iframeLoaded()" ...

I had a situation a while ago where I additionally needed to call iframeLoaded from the IFRAME itself after a form-submission occurred within. You can accomplish that by doing the following within the IFRAME‘s content scripts:


Solution 2:

A slightly improved answer to Aristos…

<script type="text/javascript">
  function resizeIframe(iframe) {
    iframe.height = iframe.contentWindow.document.body.scrollHeight + "px";

Then declare in your iframe as follows:

<iframe onload="resizeIframe(this)" ...

There are two minor improvements:

  1. You don’t need to get the element via document.getElementById – as you already have it in the onload callback.
  2. There’s no need to set the iframe.height = "" if you’re going to reassign it in the very next statement. Doing so actually incurs an overhead as you’re dealing with a DOM element.
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Solution 3:

I found that the accepted answer didn’t suffice, since X-FRAME-OPTIONS: Allow-From isn’t supported in safari or chrome. Went with a different approach instead, found in a presentation given by Ben Vinegar from Disqus. The idea is to add an event listener to the parent window, and then inside the iframe, use window.postMessage to send an event to the parent telling it to do something (resize the iframe).

So in the parent document, add an event listener:

window.addEventListener('message', function(e) {
  var $iframe = jQuery("#myIframe");
  var eventName =[0];
  var data =[1];
  switch(eventName) {
    case 'setHeight':
}, false);

And inside the iframe, write a function to post the message:

function resize() {
  var height = document.getElementsByTagName("html")[0].scrollHeight;
  window.parent.postMessage(["setHeight", height], "*"); 

Finally, inside the iframe, add an onLoad to the body tag to fire the resize function:

<body onLoad="resize();">

Solution 4:

Add this to the iframe, this worked for me:


And if you use jQuery try this code:


Solution 5:

There are four different properties you can look at to get the height of the content in an iFrame.


Sadly they can all give different answers and these are inconsistant between browsers. If you set the body margin to 0 then the document.body.offsetHeight gives the best answer. To get the correct value try this function; which is taken from the iframe-resizer library that also looks after keeping the iFrame the correct size when the content changes,or the browser is resized.

function getIFrameHeight(){
    function getComputedBodyStyle(prop) {
        function getPixelValue(value) {
            var PIXEL = /^\d+(px)?$/i;

            if (PIXEL.test(value)) {
                return parseInt(value,base);

                style =,
                runtimeStyle = el.runtimeStyle.left;

            el.runtimeStyle.left = el.currentStyle.left;
   = value || 0;
            value =;
   = style;
            el.runtimeStyle.left = runtimeStyle;

            return value;

            el = document.body,
            retVal = 0;

        if (document.defaultView && document.defaultView.getComputedStyle) {
            retVal =  document.defaultView.getComputedStyle(el, null)[prop];
        } else {//IE8 & below
            retVal =  getPixelValue(el.currentStyle[prop]);

        return parseInt(retVal,10);

    return document.body.offsetHeight +
        getComputedBodyStyle('marginTop') +

Solution 6:

Just in case this helps anyone. I was pulling my hair out trying to get this to work, then I noticed that the iframe had a class entry with height:100%. When I removed this, everything worked as expected. So, please check for any css conflicts.

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