Captions & Transcripts Accessibility Checker

The WCAG 1.2 series covers time-based media accessibility:

• 1.2.1 (Audio-only and Video-only, Level A): Pre-recorded audio-only content needs a text transcript. Pre-recorded video-only content (no audio) needs either a transcript or an audio description track
• 1.2.2 (Captions Pre-recorded, Level A): Pre-recorded video with audio must have synchronized captions that include dialogue, speaker identification, and significant sound effects
• 1.2.3 (Audio Description or Media Alternative, Level A): Pre-recorded video must have an audio description of visual-only content, or a full text alternative describing the video
• 1.2.4 (Captions Live, Level AA): Live video with audio needs real-time captions
• 1.2.5 (Audio Description, Level AA): Audio descriptions must be provided for all pre-recorded video content

These requirements affect approximately 466 million people worldwide with disabling hearing loss and 2.2 billion with some form of vision impairment who may need audio descriptions.

Media accessibility benefits far more users than just those with permanent disabilities:

• Deaf and hard-of-hearing users: Captions are essential for accessing video content. Auto-generated captions from YouTube or other platforms have error rates of 10-30%, which is insufficient for WCAG compliance
• Non-native speakers: Captions help users who speak the language as a second language follow along with audio content
• Noisy/quiet environments: 80% of social media video is watched without sound. Captions benefit everyone in offices, public transit, and libraries
• Cognitive disabilities: Reading captions while hearing audio reinforces comprehension for users with attention difficulties or auditory processing disorders
• SEO: Transcripts provide indexable text for search engines. Videos with transcripts receive significantly more organic search traffic than those without

Methods for meeting WCAG 1.2 requirements:

• Captions for video: Use WebVTT format: <video><track kind="captions" src="captions.vtt" srclang="en" label="English" default></video>. Captions must include dialogue, speaker identification, and meaningful sounds like [door slams] or [phone rings]
• Transcripts for audio: Provide a text version adjacent to or linked from the audio player. Include speaker names, dialogue, and descriptions of significant non-speech audio. Format for readability with timestamps if helpful
• Audio descriptions: An additional audio track narrating visual-only information during pauses in dialogue. For video players: <track kind="descriptions" src="descriptions.vtt" srclang="en">
• Auto-captions as starting point: Use YouTube, Rev, or Otter.ai auto-captions as a first draft, then manually review and correct every caption. Auto-captions alone do not meet WCAG — the error rate is too high for critical content

CompliScan detects <video> and <audio> elements without <track> elements for captions, descriptions, or subtitles. The scanner also identifies embedded media players (YouTube, Vimeo, Wistia iframes) and flags them for manual caption verification. Each finding indicates whether the media element is missing captions, audio descriptions, or both, along with the specific WCAG criteria violated. AI-generated guidance explains how to add WebVTT tracks and where to link transcripts. Automated tools can detect the absence of caption tracks but cannot evaluate caption quality — whether captions are accurate, properly synchronized, and include non-speech audio descriptions. Manual review is essential for caption quality. CompliScan provides the structural audit to identify all uncaptioned media across your site. For the ADA Title II deadline of April 24, 2026 and the European Accessibility Act, all pre-recorded video must have captions. Start with a free scan to find uncaptioned media.