Three Flashes
Nothing on the page may flash more than three times per second — full stop. Removes the size and threshold exceptions allowed by 2.3.1.
What it asks
No content flashes more than three times in any one-second period. Unlike 2.3.1 at level A, this AAA criterion has no exceptions for small areas or low-contrast flashes — the rule is absolute. Even a tiny status indicator that strobes at four flashes per second would fail.
How to meet it
- Remove any flashing animation faster than three Hz, regardless of size or luminance.
- For status indicators (recording, alert, “live”), use a slow pulse (one or two seconds per cycle) or a static badge with a subtle animation.
- For loading and progress feedback, prefer continuous motion (a sweeping bar, a rotating spinner) over rapid flashing.
- Strip out any third-party widget or embed that does not meet this constraint, regardless of where it sits on the page.
Common failures
- Tiny “LIVE” or “REC” indicators that strobe at four to six Hz to grab attention.
- Notification dot animations that pulse rapidly when new content arrives.
- Decorative SVG icons with high-frequency flickering animations.
Why it matters
The reason 2.3.2 exists at AAA is that the 2.3.1 thresholds, while sound, still permit a small flashing element in the corner of a screen — which can still trigger a seizure if the user happens to be looking directly at it. The AAA bar removes that residual risk. Most sites won’t formally target AAA, but for content aimed at audiences with known elevated risk (epilepsy charities, neurology clinics, special-education tools), 2.3.2 should be the working standard.