HTML <iframe> class Attribute

The class attribute on an <iframe> tag assigns one or more classnames to the inline frame element. Classes are used to style elements. Classnames are defined in a stylesheet or in a local <style> element.

Example

#

A class attribute styling an <iframe> element.

<style>
  .iframe {border:4px solid #258e94;height:450px;width:100%;}
</style>

<iframe class="iframe" src="https://www.wikipedia.org/wiki/Vincent_van_Gogh">
</iframe>

Using class

The class attribute assigns one or more classnames to the <iframe> tag.

Multiple classnames are separated by a space.

Classes (i.e. classnames) are used for styling the iframe element.

JavaScript uses classes to access one or more elements by classname.

Tip:  class is a global attribute that can be applied to any HTML element.


Syntax

<iframe class="classnames">

Values

#

Value Description
classnames One or more space-separated class names.

More Examples

A class attribute styling an <iframe> element.
Clicking the button toggles a classname that changes the border radius.



<style>
  .iframe {border: 4px solid #258e94;height:450px;width:100%;}
  .frame-rounded {border-radius: 50px;}
</style>

<iframe id="myiframe" class="iframe"
        src="https://www.wikipedia.org/wiki/Vincent_van_Gogh">
</iframe>

<br/><br/>
<button onclick="toggle();">Toggle class</button>

<script>
  let toggle = () => {
    let element = document.getElementById("myiframe");
    element.classList.toggle("frame-rounded");
  }
</script>

Code explanation

Two CSS classes are defined in the <style> element.

The class attribute in <iframe> assigns one classname.

Repeatedly clicking the button toggles the second class, changing the border radius of the <iframe>.


Browser support

Here is when class support started for each browser:

Chrome
1.0 Sep 2008
Firefox
1.0 Sep 2002
IE/Edge
1.0 Aug 1995
Opera
1.0 Jan 2006
Safari
1.0 Jan 2003

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