Accessibility Tips: Don’t Interrupt Users with Unnecessary Alerts

Well-designed websites should engage the user — but if you’re forcing users to interact with your content, you may be introducing accessibility issues.

We're talking about interruptions: Pop-ups, alerts, and other updates that are displayed automatically. The Web Content Accessibility Guidelines (WCAG) 2.2 address interruptions in Success Criterion (SC) 2.2.4, which reads:

Interruptions can be postponed or suppressed by the user, except interruptions involving an emergency.

This is a Level AAA criterion; most websites should aim for Level AA conformance with WCAG to comply with the Americans with Disabilities Act (ADA) and other digital accessibility laws (learn more about the differences between WCAG conformance levels). 

But as we’ve discussed on this blog, Level AAA criteria are strict, but still worth your attention. Here’s how following WCAG’s guidance on interruptions can help you provide a better experience for real-life users.

When are web page alerts problematic for accessibility?

In WCAG terminology, an “interruption" is anything that presents new information or refreshes the content. An example might be a stock ticker at the top of a news website, a chat window that asks users whether they need help, or time-sensitive alerts (such as timeout warnings) .

These features can be useful on a dynamic website — and we’re certainly not saying that you cannot use them (neither is WCAG, for that matter). You simply need to give people control over unnecessary notifications.

Depending on how they’re delivered, alerts may cause issues for people with disabilities:

• People who use assistive technologies such as screen readers may not be able to read the content before it updates. This is particularly common when the page has a short refresh window.
• People with attention disorders may be distracted from the content they want to read.
• People with physical disabilities may need more time to engage with the content. If the page refreshes regularly, they may be unable to read the page or finish important processes (for example, filling out forms). 

Of course, excessive interruptions can be annoying for all users, regardless of their abilities. 

From a design perspective, making interruptions and alerts optional makes sense. After all, you want to provide people with as much control over their experience as possible.

Related: Make Your Digital Media More Accessible By Providing Options

From an accessibility perspective, what types of alerts are "emergencies?"

As you might have noticed, WCAG includes an exception for “emergencies,” but the WCAG definition of an emergency is quite strict:

"A sudden, unexpected situation or occurrence that requires immediate action to preserve health, safety, or property.”

Most websites won’t have alerts that meet that definition. Session timeout alerts might qualify, since they’re related to the user’s security. 

In fact, those types of notifications are explicitly required by another WCAG criterion, 2.2.6, “Timeouts,” though that criterion simply requires that users are informed of timeouts (it doesn’t require that the timeouts are presented as alerts, or that they interrupt the user’s session). 

If your website provides updates or alert notifications, make sure they're as accessible as possible

There are plenty of good reasons to “interrupt" the user, particularly if you’re serving dynamic content. You should simply provide some sort of mechanism to allow people to postpone updates or make nonessential alerts optional. 

It’s also important to take other basic steps to ensure that notifications are accessible:

• Make sure that alerts don’t create a keyboard trap or introduce other keyboard accessibility issues. Read: Give Yourself an Accessibility Test: Don't Use a Mouse.
• Make sure that live regions have appropriate markup so that they’re compatible with assistive tech. This generally means using ARIA (Accessible Rich Internet Applications). Read: What Are ARIA Live Regions?
• If your website uses time limits, provide people with a way to turn off, adjust, or extend those limits. Read: Web Accessibility Tips: Give People Enough Time.
• Test content with a screen reader (or, even better, hire an experienced screen reader user to test your content). Read: Should Web Developers Perform Screen Reader Testing?

Once again, WCAG SC 2.2.4, “Interruptions" is a Level AAA criterion, so it may not be necessary for digital compliance — but providing users with control will only make your website more useful and intuitive. 

To learn more about the best practices of accessible design, download our free eBook: Developing the Accessibility Mindset.