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Operable
WCAG 2.3.1
Level A

What is Three Flashes or Below Threshold?

Content should not flash more than three times per second, and designers should avoid high-frequency flicker that can harm users.

Safer motion choices keep the experience usable for more people.

People with photosensitive epilepsy.
Users sensitive to flicker or rapid motion.
Anyone who prefers calm and predictable visuals.

Improves Accessibility
Safer Motion
Better User Experience
Supports Compliance

Good vs Bad Examples

Use the tabs to compare safe motion with flashing content.

Subtle motion example

Video content using gentle transitions without rapid flashes.

html

<div class="subtle-animation">Soft fade</div>

Why this is correct:

Avoids high-frequency flashing content.
Uses safe, subtle motion.
Meets WCAG 2.3.1.

Implementation Checklist

Progress0 / 6 completed (0%)

Animations stay below the flash threshold.
Rapid flashing content is avoided.
Visual effects are tested for seizure safety.
Alternatives are provided when motion is unnecessary.
Designs avoid high-frequency flicker.
Motion testing is part of release review.

Knowledge Check

Answer Yes or No to test your understanding of flashing content.

Score: 0 / 5 · Answered: 0 / 5

Should content flash more than three times per second?

Is subtle motion generally safer than rapid flashing?

Should flashing content be tested for accessibility before release?

Can a safe animation still be visually engaging?

Does WCAG 2.3.1 address flashing content?