Making media content accessible (HTML)
Looking for the C#/VB/C++/XAML version of this topic? See Making media content accessible (XAML).
If your app includes media content, ensure that you provide captions for the content. Captions are visible text equivalents of the speech and essential non-speech audio portions of a media presentation. They include all of the spoken material, and any audio effects that are required for understanding the media. Note that captions are not just for traditional video-based material; they are also required for audio-only media, such as podcasts, voice-overs in animations (including games) and presentations (including screen captures), and so on.
Captions can be closed (the display of the captions can be switched on and off by the user) or open (the captions are always visible to all users—typically burned in as part of a video track).
The following example shows how to provide a media alternative in HTML that is not part of the main recording. The three dots after label= indicate where to enter a description of the media content.
<video src="content.webm"> <track kind="captions" src="content.en.vtt" srclang="en" label="..."> </video>