W3 Accessibility Guidelines Original
Pause, Stop, Hide
For moving, blinking, scrolling, or auto-updating information, all of the following are true: (Level A)
- Moving, blinking, scrolling: For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential; and
- Auto-updating: For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto-updating is part of an activity where it is essential.
Note 1: For requirements related to flickering or flashing content, refer to Guideline 2.3.
Note 2: Since any content that does not meet this success criterion can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.
Note 3: Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so.
Note 4: An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken.
W3 Accessibility Guidelines alt2
Provide Users with a Clean, Quiet, Still Alternative
Why?
Everyone wants to keep up with the latest trends in web and app design, which may include moving images, sound, blinking lights and fast updates.
But all those features can interfere with or destroy the user experience for many people, distracting them from your key content or leaving them behind.
That's why it's key that users should be able to Pause, Stop, and Hide any moving and interactive features and experience a clean, quiet, still page.
Who it helps?
Some people with visible and invisible disabilities can be overwhelmed, confused and even made ill by images that move, blink, make sounds, scroll or update frequently.
Blinking and movement are particularly distracting for some people with a range of cognitive disabilities.
Some also might need more time to find, read, process or respond to the images and sounds.
And some assistive technology can’t process all your added features at their set speed or at all.
How?
Avoid autoplay where unnecessary.
Create a function to Pause, Stop, and Hide elements that: Move, Blink or Scroll, Update or makes Sounds.
Pausing gives users more time to experience each image and requires unpausing to continue.
Stop should be available even for short-lived sounds and images.
Hide allows users to see a page without any of the distractions.
Create a parallel text experience for those who don't want movement or sound, so they can access the information without having to watch, listen or feel.
Provide users with control over frequency of updates, except where auto-updating is essential to the function. Use jump-to-current function when users unpause, so they can get the latest information when they’re ready.
Exceptions?
There is a 5-second exception for flashing content that is necessary. [NOTE: Why??]
Features where auto-updates are essential, such as streaming video, are allowed, where the person chooses to play it.
Animations showing update progress are allowed, as removing them might make users think the function was frozen or broken.
It may not be possible to translate everything in the movement feature into text. It is important to translate that which is essential to understanding.
The difference between blinking and flashing is the speed of the change. Blinking is slower; flashes occur faster than 3 times per second and are usually brighter and can trigger seizures.
For rules about Flashes, see also 2.3. Flashes are not included in this section because pausing and stopping functions are not enough to reduce their risks.
It is ok to require all users to view a 15-second advertisement before accessing other free video content.
Technical Tips?
How to use scripts to add pause, stop, hide features.
How to add buttons for clean, quiet, still experience option.
SL 11, 12, 24.
Examples?
Carousels are not accessible for some people. It is better to have a slide show that someone clicks through at their own pace.
Videos, synchronized media presentations, animations, real-time games, advertisements, scrolling stock tickers, as well as auto-updated weather information, news and stock prices all need pause, stop, and hide features.
For "status" information like stock tickers, stock prices, weather information and news, unpausing should then jump-to-present to provide latest information.
Use pause functions in games so users can take more time for their turn and continue to participate in the competition.