Registry · Operable

2.3.1 — Three Flashes or Below Threshold

Level A Operable

Operational summary

IF content flashes, keep it to at most three flashes within any one-second period OR establish that it is below both defined general-flash and red-flash thresholds. Use safe technical analysis; do not ask a vulnerable person to watch suspected hazardous flashing.

This is an original implementation summary, not replacement normative text. The sources below supply the precise requirement, its definitions and its qualifications.

Primary sources

Registry record

Applicability and assessment start unset by design — no product has been evaluated. Instantiate the entry for an actual product, assign an owner and retain evidence.

data/wcag22-aa-registry.json

{
  "criterion_id": "2.3.1",
  "level": "A",
  "name": "Three Flashes or Below Threshold",
  "rule_definition": "../03-WCAG22-AA-REGISTRY.md#sc-2-3-1",
  "normative_source": "https://www.w3.org/TR/WCAG22/#three-flashes-or-below-threshold",
  "understanding_source": "https://www.w3.org/WAI/WCAG22/Understanding/three-flashes-or-below-threshold.html",
  "applicability_status": "NOT_EVALUATED",
  "assessment_status": "NOT_TESTED",
  "owner": null,
  "test_instance_ids": [],
  "exception_evidence_ids": []
}

This criterion as JSON →