Why Do YouTube Video Embeds Override z-index in Web Pages?

YouTube Video Embeds Override z-index

Embedding YouTube videos via iframes can lead to unexpected behaviors in web pages, particularly with elements that share the same vertical space. In certain browsers, such as Internet Explorer (IE9) and Chrome, dropdowns or other elements rendered above the video may appear partially hidden behind the iframe.

Why Does It Happen?

This behavior is not directly caused by the iframe itself but rather by an internal CSS style that YouTube includes in its embed code. This style overrides the z-index property set on the iframe, resulting in the video embedding to have a higher stack order than other elements on the page.

Solution: Adding wmode Parameter

To resolve this issue, you can modify the embed code by adding the wmode parameter with a value of either "opaque" or "transparent." This tells YouTube to disable its internal CSS style and respect the z-index of the iframe.

Example Embed Code with wmode:

<code class="html"><iframe title="YouTube video player" width="480" height="390"
src="http://www.youtube.com/embed/lzQgAR_J1PI?wmode=transparent"
frameborder="0">
</iframe></code>

Alternative Solution: JavaScript

Alternatively, you can use JavaScript to dynamically add the wmode parameter to all iframes on the page. Here's an example snippet:

<code class="javascript">$(document).ready(function (){
    $('iframe').each(function(){
        var url = $(this).attr("src");
        $(this).attr("src",url+"?wmode=transparent");
    });
});</code>

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