Captions
Captions are time-synchronized text representations of the spoken dialogue, sound effects, and other audio in a video, used by deaf and hard-of-hearing viewers and by anyone watching with sound off.
Detailed explanation
Closed captions can be turned on or off by the viewer; open captions are baked into the video. WCAG 2.1 SC 1.2.2 (Captions, Prerecorded) at Level A requires captions on all prerecorded audio in synchronized media. SC 1.2.4 at Level AA extends this to live audio.
Auto-generated captions from YouTube, Vimeo, or TikTok are typically 60–80% accurate and do not meet WCAG's "equivalent" bar. Production captions need a human review pass — at minimum to fix proper nouns, brand names, and product terminology.
How this applies to Shopify stores
Shopify's native video block does not auto-add captions. Theme video sections and product-page video need a `track kind="captions"` element pointing to a `.vtt` file. AccessComply flags videos missing a captions track.
What merchants should check next
Treat this term as a practical audit prompt, not just a definition. Check the storefront pages where the concept shows up in real customer journeys: product discovery, add-to-cart, cart drawer, checkout handoff, account login, and support contact flows. If the issue affects code, verify the rendered HTML and computed browser output after the theme change. If it affects copy or media, keep the merchant-facing wording accurate and easy to maintain.
Primary source: w3.org