Audio, video, and other forms of motion

Considerations for motion

Although motion, such as video or animated images, may draw visual interest to your page, it can also be distracting to the point it detracts from your message or makes your website difficult for certain people to navigate.

Motion may negatively impact people who are prone to migraines or suffer from vertigo, and it may be especially distracting for people who are neurodivergent.

Additionally, certain types of motion can induce seizures for people with epilepsy.

Pause / Stop / Hide

If motion lasts longer than three seconds, you must provide a web-accessible way for the user to pause, stop, or hide the content.

These Sitecore features provide automatic play / stop / hide functionality: (link)

  • Jumbotron with background video

  • Video Feature (YouTube)

  • Slide show

You may also embed video content from YouTube and Vimeo.

If you are hard-coding elements, such as a background video or HTML5 animation, you must provide a way for the website visitor to play, stop, or hide the content if the animation lasts for more than three seconds.

(https://www.w3.org/WAI/WCAG21/Understanding/pause-stop-hide.html)

Flicker rate

You must not display content that flashes at a rate of three times or more per second. Flickering content, especially content that flashes at certain frequency or within certain color ranges, can cause seizures.

(https://www.w3.org/TR/WCAG21/#seizures-and-physical-reactions)

Considerations for audio

Captions

Videos with audio tracks must have captions. Some hosting services, such as YouTube, automatically provide captions.

(https://www.w3.org/TR/WCAG21/#dfn-captions)

Background noise

If your video contains spoken word paired with background noise (ambient sound or music) or sound queues (bells, whistles, etc.), people with hearing impairments may find it difficult to distinguish the background and foreground noises. Additionally, the background noise may detract from your message if it is distracting to your audience.

Keep background noise at a minimum, or consider providing a track without background noise.

Multi-channel audio

Ensure audio plays across all audio channels.

Autoplay

Do not autoplay audio files.

Considerations for SEO

Page load time impacts search engine optimization. Ensure locally-hosted videos and audio files have been properly compressed.

Content loading from third-party sides, such as SoundCloud, Vimeo, or YouTube load asynchronously and will not impact your page load time.