What is VTT?

VTT (WebVTT - Web Video Text Tracks) is W3C standard for timed text tracks - subtitles, captions, descriptions, chapters, metadata. Plain text format starting with "WEBVTT" header. Structure: cue identifiers (optional), timecodes (00:00:01.000 --> 00:00:05.000), text content (multi-line supported). Supports: text styling (<b>, <i>, <u>, <c> classes), positioning (align:start, line:80%), voice tags (<v Speaker>), cue settings. HTML5 <video> and <audio> native support via <track> element.

VTT is modern successor to SRT (SubRip) - adds styling, positioning, metadata capabilities. YouTube, Vimeo, HTML5 video players all support VTT. Common uses: closed captions (accessibility for deaf/hard-of-hearing), subtitles (translations), audio descriptions (screen readers), chapter markers (video navigation), metadata tracks (search engine indexing). VTT enables multi-language support: one video, multiple .vtt files for different languages. CSS styling: customize font, color, background, position. WebVTT API: JavaScript access to cues for interactive experiences. Better than SRT: styling, positioning, metadata, W3C standard (future-proof).

Did you know? VTT is the only W3C-standard subtitle format - native HTML5 support!

History

W3C developed WebVTT to provide a modern, standardized subtitle format for HTML5 video, replacing proprietary and limited legacy formats.

Key Milestones

  • 2010: WebVTT draft specification
  • 2012: HTML5 <track> element
  • 2014: YouTube VTT support
  • 2016: W3C Recommendation
  • 2019: Universal browser support
  • Present: HTML5 video standard

Key Features

Core Capabilities

  • HTML5 Native: <track> element support
  • Text Styling: Bold, italic, classes, CSS
  • Positioning: Align, line, position settings
  • Voice Tags: Multi-speaker identification
  • Metadata: Custom cue data
  • Multi-Language: Multiple .vtt files per video

Common Use Cases

Captions

Accessibility (deaf/hard-of-hearing)

Subtitles

Multi-language translations

HTML5 Video

YouTube, Vimeo, websites

Chapters

Video navigation markers

Advantages

  • W3C standard (official HTML5 format)
  • Native browser support (Chrome, Firefox, Safari)
  • Text styling and positioning
  • Plain text (editable in text editors)
  • Multi-language support (multiple .vtt files)
  • CSS customization
  • Backward compatible with SRT

Disadvantages

  • More complex syntax than SRT
  • Not all video players support VTT
  • Styling not universally implemented
  • Requires UTF-8 encoding (BOM issues)
  • Manual timecode synchronization
  • Limited desktop media player support

Technical Information

Format Specifications

Specification Details
File Extension .vtt
MIME Type text/vtt
Standard W3C WebVTT (2016)
Encoding UTF-8 (mandatory)
Format Plain text (timed cues)
Timecode 00:00:00.000 (milliseconds)

Common Tools

  • Creation: Subtitle Edit, Aegisub, YouTube Studio
  • Players: Chrome, Firefox, Safari, VLC, YouTube, Vimeo
  • Editing: Any text editor (Notepad++, VS Code)
  • Conversion: FFmpeg (SRT → VTT), online converters