HTML Guide

Attribute “controlslist” not allowed on element “video” at this point.

The controlslist attribute on the <video> element is experimental, and not yet valid in the current HTML5 standard, so you should use it with caution as it may not be supported by all browsers.

Learn more:

Related W3C validator issues

Bad value “X%” for attribute “height” on element “video”: Expected a digit but saw “%” instead.

video
height

<video> elements accept a height attribute to specify the width in CSS pixels. This value can only be an integer, it should not contain units or %. If you need to specify a percentage width, you can do that with CSS.

Here’s an example of setting width and height on a video element.

<video controls width="640" height="480">
  <source src="/media/cc0-videos/flower.webm" type="video/webm">
</video>

Bad value “X%” for attribute “width” on element “video”: Expected a digit but saw “%” instead.

video
width

<video> elements accept a width attribute to specify the width in CSS pixels. This value can only be an integer, it should not contain units or %. If you need to specify a percentage width, you can do that with CSS.

Here’s an example of setting width and height on a video element.

<video controls width="640" height="480">
  <source src="/media/cc0-videos/flower.webm" type="video/webm">
</video>