Accessible Video (implementation guide)

2.7. Flashing images

There are no flashing images.

What is meant by this?

In videos, care must be taken not to use images that flash frequently or flash in quick succession. It is recommended that an image flashes no more than three times within one second.

When an image flashes, this means that it switches on and off very quickly and repeatedly or switches between different brightness levels. This can be achieved by rapidly changing the image content, background colours or brightness levels. The result is a flickering or flashing effect in which the image becomes visible and invisible at short intervals or changes greatly in brightness.

Why is it important?

It is important to avoid flashing images in videos, as staff, people who are sensitive to light stimuli may experience unpleasant or even health problems due to flickering or flashing images. Staff, people with epilepsy or light-sensitive migraines are particularly at risk. Avoiding flashing images will ensure that the videos are safe and approvable for all users.

How can I implement/check it?

To avoid flashing images in accessible videos, you can take the following measures:

• Flashing effects: Do not use fast, repeated flashing effects or animated images with strong contrast changes.
• Animations: If animations are used, make sure they are slow and smooth, without sudden flashes.
• Transitions and effects: Check all visual elements of the video, including transitions and effects, to ensure that they do not contain any flickering or flashing elements.
• Light changes: Make sure that the visual elements in your videos are calming and pleasant for the eyes, without rapid and intense light changes.