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.
People who have difficulty in reading stationary text quickly, those who will be distracted easily and those who use screen readers face difficulty in reading the content that is moving, blinking or scrolling. People with low vision and those who have attention deficit disorders will be most hit with these kind of content. On the other hand blinking content may cause seizures for certain users if the blinking content contains too much flash.
Websites that contains animations, videos, scroll tickers are the examples for these type of content. If the moving, blinking and scrolling content cannot be avoided ensure that it does not start automatically; or if it starts automatically ensure that it does not last more than 5 seconds. Alternately provide a mechanism to play/pause, stop or hide the content so that it does not distract the users in reading the other portions of the page.
Similarly auto updating content is part of many websites that provide live information. The page may entirely refresh or the portion of the page where the update occurs only be refreshed when the content is updated. This mechanism will disturb the user while reading the content of the page. Users may lose track of the content they are reading before the refresh occurred and find difficulty in perceiving the content of the page. The content updated in stock markets, score updates of live matches etc. are the examples of the websites that provide live content.
Provide a mechanism that allows the user to configure the frequency in which the refresh happens; or let the user refresh the page when required with a simple keystroke; provide an alert to intimate about the new content is available and refresh of the page will update the content. If the auto update is in parallel with other content of the page provide a mechanism to stop the auto update; control the frequency of the update unless the auto update is essential part of the website.
- A full page animations or web advertisements does not require play/pause, stop or hide buttons as they do not have any parallel content for the user to view.
- Content that blinks more than 3 times in a second is considered to be flash and they do not fall under 5 second exception.
- 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.
- 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.
- 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.
Techniques for WCAG 20 2.2.2 Level A
- G4: Allowing the content to be paused and restarted from where it was paused (General Technique)
- G11: Creating content that blinks for less than 5 seconds (general technique)
- G152: Setting animated gif images to stop blinking after n cycles (within 5 seconds) (general technique)
- G186: Using a control in the Web page that stops moving, blinking, or auto-updating content (general technique)
- G187: Using a technology to include blinking content that can be turned off via the user agent (General technique)
- G191: Providing a link, button, or other mechanism that reloads the page without any blinking content (general technique)