Prerecorded videos have synchronized captions

Uncaptioned video permanently excludes deaf and hard-of-hearing users and anyone in a sound-restricted environment. WCAG 2.2 SC 1.2.2 (Captions — Prerecorded) is a Level A requirement covering all prerecorded video with audio. Section 508 2018 Refresh explicitly requires synchronized captions. Auto-generated captions from YouTube or Vimeo average 80% accuracy and fail the WCAG requirement of being 'accurate' — they are not a compliant substitute without human review.

Supply a WebVTT caption file for every prerecorded video. Attach it with <track kind="captions"> and set default so it loads automatically.

<video controls>
  <source src="/tutorial.mp4" type="video/mp4" />
  <track
    kind="captions"
    src="/captions/tutorial-en.vtt"
    srclang="en"
    label="English captions"
    default
  />
</video>

For YouTube embeds, verify captions are enabled and human-reviewed — auto-generated captions do not satisfy WCAG 2.2 SC 1.2.2. For important content, commission a professional captioning service. Store .vtt files alongside your video assets and reference them from public/captions/.

• ID: video-captions

• Severity: high

• What to look for: Enumerate every relevant item. Look for <video>, <iframe> (YouTube, Vimeo), or video embeds. Check for <track kind="captions"> elements or references to external caption files (VTT, SRT). Verify captions include dialogue and relevant non-speech sounds (e.g., [door slams], [music plays]).

• Pass criteria: At least 1 of the following conditions is met. All prerecorded videos have synchronized captions that are accurate, complete, and include non-speech sounds.

• Fail criteria: Videos lack captions, or captions are incomplete (missing dialogue or non-speech sounds).

• Skip (N/A) when: The project contains no videos.

• Cross-reference: For user-facing accessibility and compliance, the Accessibility Basics audit covers foundational requirements.

• Detail on fail: Example: "Tutorial video in /docs lacks captions. YouTube embed on pricing page has auto-generated captions only (not accurate)"

• Remediation: Add captions to video elements using the HTML5 track element:

  <video controls>
    <source src="/video.mp4" type="video/mp4" />
    <track kind="captions" src="/captions.vtt" srclang="en" label="English" />
  </video>
  

  For YouTube videos, enable captions and verify accuracy. Use professional captioning services for important content.