Generic caption files for videos with no audio

Not all videos have audio, but this isn’t obvious for people who use closed captions. These fall into two camps: decorative and instructive.

  • Decorative videos are often used in the background of pages. They are short, perhaps three seconds long, and may loop. These don’t require a caption file.
  • Instructive videos may include a short demonstration or a time-lapse video of a scene. They have no spoken words or environmental sounds. These should have a caption file, as there’s no indication that a person who uses closed captions is missing information.

With the guidance of Sarah Margolis-Greenbaum, I’ve created a sample caption file you can use with your videos: Generic No Audio Caption (Github). This caption file will display “[No audio]” at the 2 second mark and will appear for 3 seconds.

VTT Caption File Text


00:00:02.000 --> 00:00:05.000
[No audio]

The W3C has guidance on when captions are required.

Does My Media Need Captions?

This section tells you:

  • What is required in the WCAG standard at Level A, AA, and AAA. (WCAG is introduced in the Planning page of this resource.)
  • What is needed to meet user needs, beyond WCAG. If there are no “A”s, then it is not required in WCAG.

Published by Ted

Accessibility is more than making sure images have alternate text. I work with engineers, product managers, and designers to understand how accessibility impacts the users, set realistic deadlines, and create the solutions to provide a delightful experience to all users, regardless of their physical, sensory, or cognitive ability.

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