Content should not change unexpectedly on the page. Auto-playing videos and animations should have a method to pause or stop.
Requirements for movement
Movement on the screen can be distracting to some and interfere with concentration, making it difficult to complete tasks or find the information they need. Others may become dizzy or nauseous.
For videos, including animations and blinking content, that auto-play on page load, a method to pause or stop the content is required when the animation or blinking:
- Starts automatically.
- Lasts more than five seconds. (This includes shorter clips that loop.)
- Is presented in parallel with other content.
With auto-rotating content, like carousels, some users may need more time between rotations, and assistive technology may not be able to convey the content in the allotted time. For this reason, auto-scrolling, or rotating content should also have controls to stop or pause movement and manually navigate through content.
Flashing, flickering, or strobe-light-like effects should also be avoided for those who are susceptible to seizures. A web page should not have anything that flashes more than three times in any one second.
Note on animated GIFs: The use of animated gifs is not recommended because they typically do not have a way to stop the looping animations.