Level A
What the automated checks look for
Videos have no captions
A video without captions is lost on people who can't hear it.
Who it affects. Deaf and hard-of-hearing people miss everything said in the video, as does anyone watching with the sound off.
How to fix it. Add a captions track to the video.
<video controls src="/demo.mp4">
<track kind="captions" src="/demo.en.vtt" srclang="en" label="English">
</video><video controls src="/demo.mp4">
<track kind="captions" src="/demo.en.vtt" srcLang="en" label="English" />
</video>