The WCAG Explained

Summary:
WCAG 2.3.2, "Three Flashes," builds on the previous guideline to further safeguard users from content that could induce seizures due to flashing. This criterion is more specific, focusing on flashes that are bright and large enough to cover a significant portion of the screen.

What:
This guideline specifies that web pages do not contain anything that flashes more than three times in any one-second period if the flashes are sufficiently large and bright. The key aspects are:

• Bright and Large Flashes: Flashing content must not exceed three times per second, especially when the flashes are bright and cover a substantial area of the screen.
• Reducing Seizure Risk: This focus on brightness and size is crucial as it addresses flashes that are most likely to induce seizures in susceptible individuals.

Why:
The combination of brightness, size, and speed of flashing can significantly increase the risk of triggering seizures in individuals with photosensitive epilepsy. By controlling these factors, this guideline helps in making web content safer for those individuals, ensuring accessibility and safety.

Examples and Scenarios:

1. Video Content: Videos, particularly those embedded on web pages, should be edited or designed to avoid bright, large flashes that occur more than three times per second.
2. Interactive Media: Games or interactive media with flashing effects must ensure that these effects do not fall under the dangerous criteria of being both bright and large.
3. Promotional Material: Any promotional material or advertisements displayed on websites should be checked to ensure they don't contain large, bright flashing elements that exceed the set threshold.

How to Comply:

• Websites: Carefully review all visual content, including animations and videos, to ensure compliance. Utilize tools and guidelines to measure and assess the brightness and size of potential flashes.
• Mobile Apps: Be cautious with app elements like splash screens, alerts, or any form of visual feedback that may flash, ensuring they adhere to this guideline.
• Software Applications: Ensure that no software features include large, bright flashing effects that exceed the specified flashing rate.

Exceptions:

• Essential for Functionality or Information: If the flashing is integral to the functionality or information being conveyed and cannot be presented without it, then it should be minimized and users should be warned. However, such situations are expected to be rare.