| name | apply-media-captions |
| description | Use when publishing video, audio, or any time-based media — to provide captions, transcripts, and audio descriptions for users who cannot hear or see the media content. |
| source | W3C WCAG 2.1 SC 1.2.1–1.2.5 (Level A/AA); W3C WebVTT specification; BBC Subtitle Guidelines; Netflix Timed Text Style Guide |
| tags | ["accessibility","wcag","a11y","captions","transcripts","audio-description","media","developer"] |
| related | ["design-accessibility-standards","audit-accessibility","apply-text-alternatives"] |
Implement Media Captions
Provide synchronized captions for video, transcripts for audio, and audio descriptions for visual-only content.
Why This Is Best Practice
Adopted by: WCAG 2.1 SCs 1.2.1–1.2.5 are Level A/AA — legally required by Section
508 (US), ADA, EU EN 301 549, and the UK Equality Act. Netflix was sued and settled
for $755,000 in 2012 for missing captions (NAD v. Netflix) — the landmark case that
accelerated industry adoption. All major streaming platforms (YouTube, Vimeo, AWS
Elemental MediaConvert) now provide auto-captioning as baseline infrastructure.
Impact: WHO estimates 1.5 billion people have hearing loss. Captions also benefit
users in noisy environments, non-native language speakers, and users with cognitive
disabilities. Facebook data showed 85% of videos are watched without sound — captions
improve engagement for all users, not just those with disabilities.
Auto-generated captions alone are insufficient — accuracy rates of 80–90%
produce too many errors for compliance. Human-verified captions or caption editing is
required for WCAG conformance.
