For the audio described version, see www.youtube.com An introduction into the WebVTT (Web Video Text Tracks) file format and how it is used to provide captions, subtitles and text video descriptions for HTML5 video. WebVTT is a simple line-based file format, which is currently in development at the WHATWG and under consideration for native implementation in the major browsers using the HTML5 element. The slides from this talk are available as well: html5videoguide.net