Element.scrollHeight

The Element.scrollHeight read-only attribute is a measurement of the height of an element's content, including content not visible on the screen due to overflow. The scrollHeight value is equal to the minimum height (where height includes padding but does not include border and margin) the element would require in order to fit all the content in the viewpoint without using a vertical scrollbar. It includes the element padding but not its margin.

Syntax

var intElemScrollHeight = element.scrollHeight;

intElemScrollHeight is a variable storing an integer corresponding to the scrollHeight pixel value of the element. scrollHeight is a read-only property.

Example

Problems and solutions

Determine if an element has been totally scrolled

The following equivalence returns true if an element is at the end of its scroll, false if it isn't.

element.scrollHeight - element.scrollTop === element.clientHeight

scrollHeight Demo

Associated with the onscroll event, this equivalence can be useful to determine whether a user has read a text or not (see also the element.scrollTop and element.clientHeight properties). For example:

HTML

<form name="registration">
  <p>
    <textarea id="rules">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum at laoreet magna. 
Aliquam erat volutpat. Praesent molestie, dolor ut eleifend aliquam, mi ligula ultrices sapien, quis cursus 
neque dui nec risus. Duis tincidunt lobortis purus eu aliquet. Quisque in dignissim magna. Aenean ac lorem at 
velit ultrices consequat. Nulla luctus nisi ut libero cursus ultrices. Pellentesque nec dignissim enim. Phasellus 
ut quam lacus, sed ultricies diam. Vestibulum convallis rutrum dolor, sit amet egestas velit scelerisque id. 
Proin non dignissim nisl. Sed mi odio, ullamcorper eget mattis id, malesuada vitae libero. Integer dolor lorem, 
mattis sed dapibus a, faucibus id metus. Duis iaculis dictum pulvinar. In nisi nibh, dapibus ac blandit at, porta 
at arcu. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Praesent 
dictum ipsum aliquet erat eleifend sit amet sollicitudin felis tempus. Aliquam congue cursus venenatis. Maecenas 
luctus pellentesque placerat. Mauris nisl odio, condimentum sed fringilla a, consectetur id ligula. Praesent sem 
sem, aliquet non faucibus vitae, iaculis nec elit. Nullam volutpat, lectus et blandit bibendum, nulla lorem congue 
turpis, ac pretium tortor sem ut nibh. Donec vel mi in ligula hendrerit sagittis. Donec faucibus viverra fermentum. 
Fusce in arcu arcu. Nullam at dignissim massa. Cras nibh est, pretium sit amet faucibus eget, sollicitudin in 
ligula. Vivamus vitae urna mauris, eget euismod nunc. Aenean semper gravida enim non feugiat. In hac habitasse 
platea dictumst. Cras eleifend nisl volutpat ante condimentum convallis. Donec varius dolor malesuada erat 
consequat congue. Donec eu lacus ut sapien venenatis tincidunt. Quisque sit amet tellus et enim bibendum varius et 
a orci. Donec aliquet volutpat scelerisque. Proin et tortor dolor. Ut aliquet, dolor a mattis sodales, odio diam 
pulvinar sem, egestas pretium magna eros vitae felis. Nam vitae magna lectus, et ornare elit. Morbi feugiat, ipsum 
ac mattis congue, quam neque mollis tortor, nec mollis nisl dolor a tortor. Maecenas varius est sit amet elit 
interdum quis placerat metus posuere. Duis malesuada justo a diam vestibulum vel aliquam nisi ornare. Integer 
laoreet nisi a odio ornare non congue turpis eleifend. Cum sociis natoque penatibus et magnis dis parturient montes, 
nascetur ridiculus mus. Cras vulputate libero sed arcu iaculis nec lobortis orci fermentum.
    </textarea>
  </p>
  <p>
    <input type="checkbox" id="agree" name="accept" />
    <label for="agree">I agree</label>
    <input type="submit" id="nextstep" value="Next" />
  </p>
</form>

CSS

#notice {
  display: inline-block;
  margin-bottom: 12px;
  border-radius: 5px;
  width: 600px;
  padding: 5px;
  border: 2px #7FDF55 solid;
}

#rules {
  width: 600px;
  height: 130px;
  padding: 5px;
  border: #2A9F00 solid 2px;
  border-radius: 5px;
}

JavaScript

function checkReading () {
  if (checkReading.read) {
    return; 
  }
  checkReading.read = this.scrollHeight - this.scrollTop === this.clientHeight;
  document.registration.accept.disabled = document.getElementById("nextstep").disabled = !checkReading.read;
  checkReading.noticeBox.innerHTML = checkReading.read ? "Thank you." : "Please, scroll and read the following text.";
}

onload = function () {
  var oToBeRead = document.getElementById("rules");
  checkReading.noticeBox = document.createElement("span");
  document.registration.accept.checked = false;
  checkReading.noticeBox.id = "notice";
  oToBeRead.parentNode.insertBefore(checkReading.noticeBox, oToBeRead);
  oToBeRead.parentNode.insertBefore(document.createElement("br"), oToBeRead);
  oToBeRead.onscroll = checkReading;
  checkReading.call(oToBeRead);
}

Specifications

Browser compatibility

[1] In Firefox versions earlier than 21, when an element's content does not generate a vertical scrollbar, then its scrollHeight property is equal to its clientHeight property. This can mean either the content is too short to require a scrollbar or that the element has a CSS style overflow value of visible (non-scrollable).

See Also

• MSDN: scrollHeight Property
• MSDN: Measuring Element Dimension and Location (Content moved.)
• MSDN: Measuring Element Dimension and Location with CSSOM in Windows Internet Explorer 9
• Element.clientHeight
• HTMLElement.offsetHeight
• Determining the dimensions of elements