Editing & Post-Production
WebVTT
Also called: VTT, .vtt
A .vtt file opens in any text editor. You get a WEBVTT header, then a list of cues, each with a start and end timestamp and the text to display. Positioning and basic styling can be attached per cue, which is what separates it from the older SRT format. Browsers read it natively through the HTML5 track element, and YouTube accepts it as a caption upload, so it is the safe default for moving subtitles between platforms. One gotcha. Timestamps use a full stop for fractions of a second and SRT uses a comma. That single difference is the usual reason a converted file refuses to load.