Level AOperable2.3.1

WCAG 2.3.1: Three Flashes or Below Threshold

Content does not contain anything that flashes more than three times per second.

ADA Relevance: Level A is the minimum baseline. Failing this criterion is a clear ADA violation and one of the easiest violations for plaintiff attorneys to identify.

Why Three Flashes or Below Threshold Matters

Flashing content can trigger seizures in users with photosensitive epilepsy. This is a safety issue, not just a usability concern.

How to Test for WCAG 2.3.1 Violations

Review all animations, videos, and dynamic content for flashing. Use the PEAT (Photosensitive Epilepsy Analysis Tool) for video content.

How to Fix WCAG 2.3.1 Violations

Don't use content that flashes more than 3 times per second. If unavoidable, ensure the flashing area is small (less than 25% of 10 degrees of visual field) and below general and red flash thresholds.

Industries Most Affected by Three Flashes or Below Threshold Violations

These industries commonly fail WCAG 2.3.1 due to the nature of their website content and functionality:

Three Flashes or Below Threshold by Platform

Different platforms have different levels of built-in support for WCAG 2.3.1:

WCAG 2.3.1 FAQ

What does WCAG 2.3.1 Three Flashes or Below Threshold require?

WCAG 2.3.1 requires that content does not contain anything that flashes more than three times per second. This is a Level A criterion under the Operable principle, meaning it is a minimum baseline requirement.

How do I test for WCAG 2.3.1 violations?

Review all animations, videos, and dynamic content for flashing. Use the PEAT (Photosensitive Epilepsy Analysis Tool) for video content.

Is WCAG 2.3.1 required for ADA compliance?

Yes. WCAG 2.3.1 is a Level A criterion, and courts consistently reference WCAG 2.1 AA as the standard for ADA compliance. Failing to meet this criterion creates legal exposure for ADA lawsuits, which typically settle for $10,000 to $75,000+.

What happens if my website fails WCAG 2.3.1?

Failing WCAG 2.3.1 Three Flashes or Below Threshold means flashing content can trigger seizures in users with photosensitive epilepsy. This is a safety issue, not just a usability concern. This violation is detectable by automated scanning tools that ADA plaintiff attorneys use to identify lawsuit targets. ADA CodeFix can scan your site for this specific violation and provide AI-generated code fixes.

Test Your Site for WCAG 2.3.1 Violations

ADA CodeFix automatically scans for Three Flashes or Below Threshold violations and provides AI-generated code fixes — not overlay widgets.

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