Web developers have plenty of tricks for keeping users engaged, and when properly implemented, most of those tricks fall in line with the best practices for accessibility. For instance, keeping consistent page navigation elements will allow users to find what they’re looking for, resulting in better user retention — and users won’t have to go to extreme lengths to use the website naturally.
Unfortunately, some engagement techniques can be annoying and frustrating. Few design choices are quite as controversial as autoplay. When audio or video content starts playing automatically without any human input, the user experience suffers.
Autoplay has few benefits (and plenty of drawbacks)
For media publishers, autoplay videos might seem like a necessary evil. According to The New York Times, video ads generate 20 to 50 times more revenue than display ads, and the simplest way to get users to watch videos is to start them automatically.
But many modern browsers mute or pause autoplay media by default, and most of the purported benefits of autoplay — more user engagement, better user retention — are wildly overstated. In a 2016 survey (PDF) performed by consumer education website Consumer World, 92.3 percent of web users said that they found autoplay "annoying," and 76 percent of respondents said that they were likely to try to silence the sound immediately. Most users said that if they couldn’t silence the sound, they’d leave the site.
For people without disabilities, autoplay media is an annoyance, but for people with some disabilities, autoplay can make a site unusable. Some of the possible unintended effects:
- People with cognitive disabilities may find media confusing or distracting.
- Media may trigger seizures and other physical reactions.
- Autoplay media can prevent users from navigating a site in a natural, intuitive way.
- Autoplay can prevent users from hearing or otherwise conflict with screen readers, frustrating users who utilize text-to-speech software.
Over the last few years, many high-traffic sites have taken steps to limit autoplay to better accommodate their users, but major accessibility issues involving autoplay videos have made headlines. In 2015, Twitter pulled two advertisements from their video platform Vine. The ads featured six seconds of flashing video, which reportedly triggered epilepsy episodes from some users. In February 2020, streaming service Netflix added the ability to turn off autoplay. Prior to the update, trailers and episodes would play automatically, regardless of the user’s preferences.
Even so, many sites rely on autoplay despite the significant accessibility concerns. Real users prefer to experience the internet on their own terms — and with plenty of options for experiencing content.
Use best practices when incorporating media
In the vast majority of situations, the safest course of action is to avoid autoplay entirely. While no site is 100 percent accessible, autoplay is easy to avoid, and its limited benefits are easily outweighed by the accessibility concerns.
When developers do decide to incorporate media, they need to take appropriate precautions to prevent a major accessibility failure. Under WCAG guidelines, any media that autoplays should have controls that allow the user to pause or stop playback. Rather than automatically playing video, provide users with options and give relevant warnings for flashing lights, loud sounds, and other possible triggers.
Developers should choose play/pause controls that have an obvious function, and even when following best practices, they shouldn’t take for granted that the media will play successfully without user input. Writing for Google, Chrome developer François Beaufort notes that developers should never assume that a video will play and should never show a pause button when the video is not actually playing.
When media must play automatically, the user should be able to immediately stop playback with simple commands. Few situations actually call for this type of functionality — while multimedia content can be valuable, the safest course of action is to allow the user to control all aspects of playback.
Websites should also provide both captions and transcripts for videos, along with alternative resources for other types of multimedia content (for instance, podcast transcripts and image alt descriptions). This approach avoids alienating users and makes the page easier to use with screen readers and other adaptive computer accessories.