About .VTT File Format
To work with VTT files in Anycount, let’s get to know a little more about this format.
VTT is the Extension used by the WebVTT (Web Video Text Tracks) subtitle format. It is a World Wide Web Consortium standard for timed text that uses the HTML5 element. WebVTT is based on the hugely popular SRT format though not fully compatible with it. The WebVTT specification is still in draft stage is already supported by all major browsers.
Link:
WebVTT (detailaed description of the standard)