Media Files

Media files should add value, not hide essential information. W3C guidance identifies captions, transcripts, description of visual information, and accessible media players as the core parts of accessible media. Planning these items before recording reduces rework and makes publication easier. 

 

Before you publish media

Keep key information on the webpage itself, including dates, links, deadlines, and contact details. Use clear speech, low background noise, readable on-screen text, and language that does not depend on sight or color alone. If users need to hear or see the media to understand something important, plan the accessible version before the recording is final. 

 

What each media type needs

Use this as a starting point:

  • Audio-only: provide a transcript.

  • Video with speech: provide captions and a transcript.

  • Video with important visuals that are not spoken aloud: provide description of visual information or a descriptive transcript.

  • Video-only or silent demonstrations: provide a descriptive transcript or another equivalent text alternative that explains the action.

 

W3C’s media guidance distinguishes captions, transcripts, and visual description because they solve different access needs. 

 

Captions

Captions are synchronized text for the speech and non-speech audio needed to understand the media. They are different from translated subtitles: W3C uses “captions” for the same language as the audio and “subtitles” for translated audio. Good captions include speaker identification when needed and meaningful sound cues, not just dialogue. 

 

Transcripts

A basic transcript is a text version of speech and non-speech audio. A descriptive transcript also includes the visual information needed to understand the video. Descriptive transcripts are especially important for people who are both Deaf and blind. 

 

Describe important visuals

If the video contains charts, demonstrations, on-screen text, steps, or actions that are not already spoken aloud, add description of the visual information. For many training or presentation videos, the easiest approach is integrated description: write the script so the speaker says the important visual details out loud. When that is not possible, provide a separate described version or another supported description method. 

 

Use an accessible media player

Choose a player that works with keyboard navigation, visible focus, screen readers, speech input, and zoomed interfaces. Helpful features include caption controls, adjustable caption display, and interactive transcripts. 

 

Before publishing

Use this quick review before posting media:

  • Important page information also appears in HTML on the webpage.

  • Captions were added where needed.

  • A transcript was provided.

  • Important visual information was spoken or described.

  • On-screen text is readable and high contrast.

  • The media player works with keyboard navigation.

  • The media was reviewed on desktop and mobile.

 

Related guidance: Content Development, Links, Image Files, and Page Description.