Formats & playback 5 min read
SRT vs VTT vs ASS: Subtitle Formats Compared and Converted
Three subtitle formats dominate: SRT (plain text + timestamps, plays everywhere), WebVTT (HTML5 players, inline styling), ASS (full typography — fonts, positions, karaoke effects). Converting between them loses only what the target cannot express.
Compatibility map
- SRT: video players (VLC, IINA, hardware TVs), most editors; no styling beyond italic markers.
- VTT: HTML5 <track>, web players; supports positioning and basic cues styling.
- ASS: VLC/mpv render it fully; players and platforms mostly ignore advanced tags or strip them.
Conversion semantics
SRT ↔ VTT is near-lossless (format headers differ; timestamps use , vs .). Anything → ASS preserves text and timing but adds no styling you did not have. ASS → SRT drops typography — positions, colors, fonts are gone; verify karaoke-style files before batch converting.