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WCAG 2.3.1

Three Flashes or Below Threshold

  • Level A
  • WCAG 2.0
  • Principle 2: Operable
  • EN 301 549: 9.2.3.1

In short

Nothing flashes more than three times per second, or is below the flash thresholds.

How Percelia tests it

Percelia detects some cases automatically with rules; the rest needs AI or human judgment. Anything ambiguous goes to human review.

This criterion is judgment-bound and is always put to a human reviewer at Percelia, even at high confidence.

Official source

W3C Understanding document (w3.org)

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