Dear WCAG Plus Forum members,
Let's continue our journey through the Web Content Accessibility Guidelines (WCAG) 2.1 with a fundamental criterion that ensures multimedia content is accessible to everyone: Success Criterion 1.2.1: Audio-only and Video-only (Prerecorded). This criterion is a Level A requirement, meaning it's considered an essential baseline for web content accessibility.
What does Criterion 1.2.1 require?
In simple terms, this criterion ensures that if you have audio or video content that doesn't include other sensory elements (e.g., a video without significant audio or an audio without video), an equivalent textual or audio alternative must be provided.
- 1.2.1 Audio-only (Prerecorded): For prerecorded audio-only content (like a podcast or a radio recording), an "alternative for time-based media" (typically a text transcript) must be provided.
- 1.2.1 Video-only (Prerecorded): For prerecorded video-only content (like a silent video or an animation without significant audio), an "alternative for time-based media" (typically a text description or an audio description track) must be provided.
This criterion addresses fundamental barriers for various user groups:
For Audio-only Content:
- For deaf or hard of hearing individuals: A text transcript is the only way to access spoken content or significant sounds.
- For those with cognitive disabilities or learning difficulties: A transcript can facilitate comprehension and allow them to review content at their own pace.
- In environments where audio cannot be heard: It enables content access in situations where audio is unavailable or inappropriate (e.g., office, public places).
- For blind or low vision individuals: A text description or an audio description track is essential to understand what is visually happening in the video. Without it, the content is inaccessible.
- In environments where viewing is not possible: Users who are driving, listening in the background, or unable to watch the screen.
1. Transcripts for Audio-only:
- Format: A complete text transcript of all dialogue and significant sounds. It should be accessible directly on the page or via a clear link.
- Quality: It must be accurate, include speaker identification, and, if relevant, describe non-verbal sounds that contribute to understanding (e.g., "[laughter]", "[upbeat music]").
- Additional Benefits: Transcripts also improve SEO and allow users to copy/paste parts of the text.
- Text Description: If the video is short and simple (e.g., an animated logo or a brief visual sequence without audio), a concise text description (e.g., an `alt` attribute on an embedded video, if appropriate, or immediately adjacent text) may suffice.
- Audio Description: For more complex videos where visual information is crucial for understanding, an audio description track is needed. This is additional narration that describes what is visually happening, inserted into natural pauses in the original audio, or provided as a secondary audio track.
- Forgetting Alternatives: Not providing transcripts or descriptions at all.
- Incomplete/Inaccurate Alternatives: Transcripts with errors or descriptions that fail to capture all relevant visual information.
- Confusing with Captions/Subtitles: These (covered by Criterion 1.2.2 and subsequent) are for videos with audio and do not satisfy the requirement for *only* video or *only* audio content.
We invite the community to share their experiences:
- What tools do you use to create transcripts or audio descriptions?
- Have you encountered any particular challenges in implementing this criterion?
- Can you share examples of good practices or common mistakes you've come across?
Warm regards,
Michele (wcgadmfrm)
WCAG Plus Forum Team