What is a VTT File?

what-is-a-vtt-fileCreating subtitles and captions involves knowing about VTT files. Whether you are trying to learn how to create a VTT file online or have hired a professional transcription service, it is important to know the basics of the VTT file format and what it means. The WebVTT format provides needed information for captions, subtitles, chapters and content navigation, metadata, and video descriptions. This format replaced the Web SRT format (or Web Subtitle Resource Tracks) in 2010.

Just What is a VTT File?

The VTT file format displays time text tracks like captions and subtitles using the <track> element. If you don’t know, the HTML <track> element is a child of media elements like <video> or <audio>. This allows you to automatically handle subtitles. This specific format is entirely text based. There is no video date in the format. You must encode using UTF-8. The data and the tracks do have a basic API (Application Programming Interface) that allows playback of text to test timing. These are important to know whether you have to create a VTT file online, using a professional service, or have to quality check the subtitles and captions on a project.

Some Important Terms

Before you embark on creating VTT file formats, you need to be familiar with several terms. The BOM is the optional byte order. The cue lets you know where in the timecode the viewer will see the text. Comments are optional. They can be very helpful in providing useful information. Keep in mind that the comments are not seen by the viewers of the video.

Dissecting the Basic Structure of WebVTT

There are several key components prevalent in the basic structure of the WebVTT format. Not all components must be present, though some are mandatory. Keep in mind that there are some detailed rules when creating the VTT file involving use of spaces, ampersand characters, less-than signs, and other text.

Below is a very basic example of the format.

  1. The BOM or “optional byte order” mark is followed by the string “WEBVTT”.
  1. There is an optional text header. This is to the right of WEBVTT.
  1. You may add a description to the WEBVTT file in this section within certain parameters.
  1. Insert a blank line.
  1. Zero or more comments and/or cues.
  1. Zero or more blank lines.

While there are many ways to write this out, this basic outline for the VTT file format is a good start. Contact a professional transcription service about how you can use subtitles and transcriptions in your next video production.