Captions (Live)
Captions are provided for all live audio content in synchronized media (livestreams, live shopping events, real-time webinars).
What it requires
WCAG 2.0 SC 1.2.4 extends the captioning requirement to live audio. A live shopping event, a livestreamed product launch, or a real-time webinar embedded on the storefront must provide captions in real time.
Live captions are typically provided by a stenographer (CART) or by a real-time speech-to-text service. Auto-generated live captions vary in accuracy by service; YouTube Live and TikTok LIVE auto-captions are the most-used. WCAG does not mandate a specific accuracy threshold, but the captions must convey the content equivalently.
Common Shopify failure
A Shopify-embedded YouTube Live or Twitch shopping stream displayed without captions, or with auto-captions disabled at the source. Live launch events streamed to a custom video block without a captioning service.
How to fix it
For YouTube Live embeds, ensure auto-captions are enabled at the broadcast source. For premium events, contract a CART or live-captioning vendor (3PlayMedia, Ai-Media). Document the captioning approach in the accessibility statement.
Primary source: W3C — WCAG 2.0 Understanding 1.2.4