• Success Criterion 2.3.1
  • Conformance level A

Content Flashing Faster Than 3 Times per Second

2.3.1 — Three Flashes or Below Threshold

Scenario

Setting

An email client's compose window

What’s wrong

A loading animation flashes bright red and white more than three times per second while the compose window saves a draft, with no way to disable or reduce it.

Example 

setInterval(() => {
  banner.style.background = banner.style.background === "red" ? "white" : "red";
}, 150); // runs while the draft autosaves

Why it matters

A user composing an email gets a rapid red-white flash every time a draft autosaves, with no way to turn it off.

How to test

Run the content through the Photosensitive Epilepsy Analysis Tool (PEAT): confirm no flash exceeds 3 times per second within any one-second window.

How to fix

A static status label communicates saving without any flash risk.

<span class="saving-label" role="status">Saving draft...</span>
<!-- remove the flashing background interval -->

Outcome

A user keeps composing their email through every autosave without any flashing indicator on screen.

Who is affected

Users with photosensitive epilepsy risk a seizure from the rapid red-white flash during routine autosave.

Learn more

Related scenarios