What Is a VTT File?
A VTT file is a plain text file format used to synchronize text with audio or video content, most notably within HTML5 video players on the web. It dictates exactly when specific dialogue, sounds, or descriptions should appear on screen.
Because it is plain text, a VTT file does not contain actual video or audio data. Instead, it acts as a companion document that web players read in real-time alongside your media. This makes VTT an essential standard for modern web speech to text integration.
The Basic WebVTT Cue Structure
VTT files have a specific structure to ensure web browsers can read them correctly. Every VTT file must begin with a WEBVTT header. Following the header, the subtitles are divided into individual blocks known as cues.
The timecode format for a VTT cue follows Hours:Minutes:Seconds.Milliseconds, always using a period (.) to separate seconds from milliseconds.
WEBVTT
00:00:01.500 --> 00:00:04.250
This is the first subtitle appearing on a web player.
00:00:04.300 --> 00:00:06.800
Notice the period used before the milliseconds
in the timecode.Each cue block typically includes:
- The timecode: A start time and an end time separated by an arrow (
-->). - The cue text: The actual dialogue to be displayed on screen.
- A blank line: Indicates the end of the current cue and the start of the next.
When Is VTT Useful?
VTT is specifically designed for the modern web. It is the ideal format when you need to display subtitles directly in a web browser using standard HTML5 tags.
Web Development
If you are a developer embedding video into a website, you can use the native HTML <track> element to easily load a VTT file alongside your video source.
Web Platforms
Many modern online video platforms, e-learning management systems, and media players prefer or require the VTT format for accessible web captioning.
How VTT Differs from SRT and TXT
While all three formats are text-based, they serve distinct purposes in media workflows.
- SRT (SubRip): SRT files are the older, more traditional format. They are extremely simple, lack the
WEBVTTheader, and use a comma for milliseconds. SRT is highly supported by desktop video editors. - TXT (Plain Text): Contains only raw spoken words with absolutely no timestamps. TXT is meant for reading or publishing as an article, but cannot be synced to a video player.
Exporting VTT Transcripts from Konthora
Konthora creates the standalone caption/transcript files, but it does not burn captions permanently into video. It provides the raw VTT file for you to upload to your web player or publishing platform.
When you transcribe audio on Konthora, our system generates precise timed data. You can easily export this data as a WebVTT file. You can also customize how the text is grouped—by sentence or paragraph—using our options for transcription timestamps.
Ready to create WebVTT captions?
Upload an audio or video file to generate a timed VTT transcript automatically.