Checkpoint 1.9 - Flash
Avoid blinking or flashing content
WCAG 1.0 Priority 2
WCAG Guideline 7. Ensure user control of time-sensitive content changes.
Flashing or blinking can cause photo-sensitive seizures in susceptible individuals. The flicker rate is also hard to predict due to different settings of end user screens. Flashing or blinking of the content must therefore be avoided altogether.
Do not cause screen to flash or flicker.
- View the web pages in a browser to ensure that no images or other screen components cause flashing or blinking on the screen.
- Internet Explorer - AIS toolbar:
Tools > Simulations > Flickering Images Demo
The original source of this information is located on the W3C web site (www.w3.org/TR/WCAG10-TECHS/#tech-avoid-blinking)