Techniques for WCAG 2.0

Skip to Content (Press Enter)

-

G15: Using a tool to ensure that content does not violate the general flash threshold or red flash threshold

Applicability

Applies to any technology

This technique relates to:

Description

The purpose of testing for violations of the general and red flash thresholds is to allow people who have photosensitive seizures to view Web sites without encountering material that is likely to cause a seizure. Warnings can be provided but people may miss them and children may not be able to read or understand them. With this technique all material is checked and if it violates flash or red flash thresholds it is either not put on the site or it is modified so that it does not violate the thresholds.

Note 1: There are some simple tests that can be run for particular simple types of flashing. For example:

Note 2: For all other types, a tool is needed to keep track of all the factors and apply them to the video on a time-continuous basis.

Examples

Resources

Resources are for information purposes only, no endorsement implied.

Tests

Procedure

Check to see to see that content does not violate the general flash and/or red flash threshold

  1. use a tool to determine that neither the General Flash nor Red Flash threshold were exceeded

Expected Results

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.

Techniques are Informative

Techniques are informative—that means they are not required. The basis for determining conformance to WCAG 2.0 is the success criteria from the WCAG 2.0 standard—not the techniques. For important information about techniques, please see the Understanding Techniques for WCAG Success Criteria section of Understanding WCAG 2.0.