WCAG
Web Content Accessibility Guidelines
The W3C-published accessibility standard. Captions for prerecorded video are required at WCAG 2.1 Level A.
In depth
WCAG (Web Content Accessibility Guidelines) is the W3C's standard for making web content accessible. The current version is WCAG 2.2, with WCAG 3 in draft. For video, the relevant criteria are 1.2.2 (captions for prerecorded media — Level A), 1.2.4 (captions for live media — Level AA), and 1.2.5 (audio description — Level AA). Most enterprise and government procurement requires WCAG 2.1 AA conformance, which makes high-quality captions effectively mandatory.
When to use it
Reference WCAG when delivering to enterprise, government, education, or any audience with formal accessibility requirements. Captions should follow CC/SDH conventions: speaker labels and significant non-speech sounds.
Frequently asked
Are auto-generated captions WCAG-compliant?+
Probably not. WCAG 2.1 success criterion 1.2.2 requires captions to be 'equivalent' to the audio — auto-captions with 5–10% error rates often fail this test in audit. Hand-correct or risk failing review.
Does WCAG specify font size or position?+
Not directly for captions, but related criteria (1.4.4 Resize Text, 1.4.10 Reflow) imply captions should remain readable when the user resizes. Closed captions in a player UI satisfy this naturally; burned-in captions don't.