WCAG (Level AAA) SC 2.2.4 Interruptions (w3.org)
Issue description
WCAG 2.2.4, “Interruptions” recognizes that unexpected interruptions can be highly disruptive and disorienting for users, especially those with cognitive disabilities or those who rely on assistive technologies. This Level AAA criterion aims to minimize interruptions and provide users with greater control over their browsing experience.
Web pages often present interruptions that can interfere with a user’s focus and flow. These can include:
- Pop-up windows: Unexpected pop-up windows that appear while the user is trying to read or interact with the content.
- Modal dialogs: Modal dialogs that require immediate attention and prevent the user from interacting with the rest of the page.
- Auto-playing videos or audio: Videos or audio that start playing automatically, disrupting the user’s concentration.
- Notifications and alerts: Notifications or alerts that appear unexpectedly and require immediate action.
These interruptions can be particularly problematic for users with:
- Cognitive disabilities: Users with cognitive disabilities might find it difficult to refocus after an interruption or to understand the context of the interruption.
- Attention deficit disorders: Interruptions can be especially disruptive for users with attention deficit disorders, making it hard to maintain focus on the task at hand.
- Assistive technology users: Interruptions can interfere with the operation of assistive technologies, such as screen readers.
WCAG requirements
This guideline requires that any changes of context that are initiated by the web page and are not requested by the user must:
- Be predictable: Users should be warned about the interruption before it occurs.
- Be dismissable: Users should be able to dismiss the interruption without losing their place or data.
- Provide a mechanism to postpone or suppress: Users should be able to postpone or suppress the interruption, so they can address it at a more convenient time.
Exceptions
- User-requested changes: Changes of context that are initiated by the user (e.g., clicking a link to open a new window) are exempt.
- Essential interruptions: Interruptions that are essential for security or functionality (e.g., a warning about unsaved data) are exempt.
Essentially, this guideline promotes a more user-controlled and predictable browsing experience. It minimizes disruptions and allows users to manage interruptions in a way that suits their needs and preferences.
Related requirements
The following WCAG source criteria are often related to this as well. They can provide additional insights into specific challenges you may be encountering.
- WCAG (Level A) SC 2.2.1 Timing Adjustable
- WCAG (Level AAA) SC 2.2.3 No Timing
- WCAG (Level AAA) SC 2.2.5 Re-authenticating
- WCAG (Level AAA) SC 2.2.6 Timeouts
Who this issue impacts
Follow the links for additional information on user impairments:
Suggestions for remediation
Remediating WCAG 2.2.4 “Interruptions” involves minimizing unexpected changes of context and giving users more control over interruptions. Here’s how:
Make interruptions predictable
- Provide warnings: Warn users about interruptions before they occur. For example, before displaying a modal dialog, provide a message like, “You will be asked to confirm your action in a pop-up window.”
- Clear labels and instructions: Use clear labels and instructions to help users understand the purpose of the interruption and what they need to do.
Make interruptions dismissable
- Close buttons: Provide clear and accessible close buttons for pop-up windows and modal dialogs. Ensure they can be operated with a keyboard.
- Escape key: Allow users to dismiss interruptions using the Escape key.
- Clicking outside: Allow users to dismiss modal dialogs by clicking outside the dialog window.
Provide controls for postponing or suppressing
- Postpone: Offer a way for users to postpone the interruption, such as a “Remind me later” option.
- Suppress: Provide a way for users to suppress certain types of interruptions altogether, such as disabling notifications or pop-ups.
- User settings: Allow users to customize their preferences for interruptions in a dedicated settings area.
Minimize unnecessary interruptions
- Avoid pop-ups: Use pop-up windows sparingly and only when necessary. Consider alternative methods, such as inline expansion or in-page notifications.
- Control autoplay: Prevent videos or audio from playing automatically. Allow users to initiate playback.
- Consolidate notifications: Group multiple notifications together or provide a notification center where users can review them at their convenience.
Testing
- Keyboard testing: Test all interactions and interruptions using only the keyboard to ensure they are accessible and dismissable.
- Assistive technology testing: Test with screen readers to ensure that interruptions are announced properly and do not disrupt the user’s flow.
- User testing: Conduct user testing with people with cognitive disabilities to get feedback on the usability and impact of interruptions.
Example
Instead of a pop-up window appearing unexpectedly, you can:
- Provide a warning: Display a message before the pop-up appears, informing the user about the upcoming interruption.
- Offer a “Remind me later” option: Include a button in the pop-up that allows users to postpone the interruption.
- Provide a setting to disable pop-ups: Allow users to disable pop-ups altogether in their user preferences.
By implementing these techniques, you can create a more predictable and user-controlled experience, minimizing disruptions and making your website more accessible to everyone, especially those who are sensitive to interruptions.
