What is WebVTT?

The programming of closed captioning and subtitles into videos has grown fast since the availability of online videos. It has grown from being embedded into the video to being programmed separately. There are several formats for caption encoding but the common two are the SRT format and the WebVTT format. The latter was originally a SRT component but due to incompatibility issues it had to be separated. Its original name however was WebSRT standing for web subtitle resource tracks up to the year 2010 when it was changed to WebVTT an acronym for web video text track. The methods of encoding are really similar, the major difference being that you might require a SubRip program for the case of SRT and just a simple text editor will do for WebVTT. Webvtt enables you to edit the color and font of the captioned text. Not every caption formatting method has the option of editing the appearance of the text; this makes WebVTT among the best formats. If the programmer is already used to using the SRT format he might not feel a large difference when it comes to using WebVTT. Webvtt is among the latest methods of caption encoding.

WebVTT And Closed Captioning

WebVTT format is in plain text but must follow a certain order or arrangement. It must start with the phrase WEBVTT which should be written by use of upper case letters. Once done writing the phrase, a blank line follows. After the blank line, the time frame is written. When writing the time frame, start by the time that the subtitle will appear followed by when it is supposed to disappear. The order of time should be hours minutes seconds then milliseconds which are separated by a comma. The time text is followed by the desired caption or subtitle text. The caption is followed by a blank line which shows the end of the first caption. The encoding must be done by use of UTF-8 character encoding. WebVTT is mainly used concurrently with HTML5 to enable WebVTT to be synchronized with the video or media. When saving the encoded caption it is better to save it using the .vtt extension so that the media players can be able to read it. Each time frame and its subtitle should be labeled as a cue which is written in a line of its own just above the time frame. Besides using CSS, people can customize the font and add visual effects to create an original style. That's really powerful.


00:18.000 --> 00:20.000
<v John Smith> And where are Steve and Rick

00:20.000 --> 00:21.000
<v Steven Smith> They both are at the museum

00:21.000 --> 00:22.000
<v John Smith> Oh really? That's great!

SRT is a more complex method when compared to WebVTT. That is why most people prefer WebVTT. The order of encoding is also very important in this case. The first line is usually a number labels the caption or subtitle. It is then followed by a time frame starting with when the caption is supposed to appear followed by when to disappear. The order of writing time is the same as that for WebVTT the only difference being that in this case the hour minutes seconds and milliseconds are separated using a full stop as opposed to using a comma. Once the time limits have been indicated what follows is the actual caption or subtitle text. It is then closed by a blank line. In both cases a blank line indicates the end of a one caption and the beginning of another. The SRT is then saved using .srt extension.

Comparing the two, they might look similar but there are differences. The common differences are that WebVTT format must start with the phrase WEBVTT while in the case of SRT formatting it goes straight to encoding. Another difference is that the time framing in WebVTT is separated using a comma while in SRT a full stop is used. Identification of each cue in WebVTT formatting is optional while in the case of SRT it is compulsory. The main difference being that WebVTT must have UTF-8 encoding while this is not a must in the case of SRT.

WebVTT makes captioning much easier and faster. Captioned videos tend to pass information to the viewer more comprehensively than non captioned videos.These are just a few of the reasons why WebVTT has become quite popular among users today.

The video encoding API
for developers & teams.
Need a Video Encoding Platform for your project?
Create your free account