Novus Convert
Convert files
Document format

ASS converter

An .ass file is an Advanced SubStation Alpha subtitle script: an INI-like document whose [Events] section holds Dialogue lines with start and end times, a named style, and text that may carry inline override tags. It is the format fansub and anime communities standardised on because it can position, colour, and animate captions rather than only time them.

Private for supported formats — processed in your browser

Convert supported files

Runs on your device

Drop ASS files here

Batch files can each use a different output. Nothing uploads for local conversions.

Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.

Where ASS comes from

SubStation Alpha appeared in 1995 as the script format of Kotus's SubStation Alpha editor for the Amiga-influenced PC scene. The v4.00+ revision, published as Advanced SubStation Alpha around 2002, added a richer style table and the override-tag vocabulary; Aegisub and libass then made it the de facto styled-subtitle format for Matroska releases.

How ASS works

  • The script is divided into [Script Info], [V4+ Styles], and [Events] sections, each with its own Format line naming the fields that follow.
  • Dialogue timing uses H:MM:SS.cc — one hour digit and centisecond precision, not milliseconds.
  • Inline override tags in braces ({\i1}, {\pos(...)}, {\fad(...)}) control italics, position, fades, and transforms.
  • The commas that separate Dialogue fields are positional, so cue text is everything after the final format field and may itself contain commas.
  • Line breaks inside a cue are written \N (hard) or \n (soft), never as literal newlines.

When to use ASS

  • Styled and positioned captions muxed into Matroska releases
  • Karaoke timing where each syllable carries its own effect
  • Preserving typesetting work done in Aegisub
  • Converting a styled script down to a plain caption format for a player that cannot render it

Strengths and limitations

Strengths

  • The most expressive plain-text subtitle format in common use
  • Precise positioning and per-style typography that SubRip cannot express
  • Rendered identically anywhere libass is available

Limitations

  • Styling and positioning are lost the moment the file is converted to SubRip, WebVTT, or a lyric format
  • The positional-comma field layout makes naive parsers fragile
  • Browsers cannot render it natively; playback needs a libass-backed player

Compatibility

VLC, mpv, MPC-HC, and anything else built on libass render .ass faithfully, and Aegisub remains the standard authoring tool. Browsers and most streaming platforms do not accept it, which is why converting to WebVTT or SubRip is the usual delivery step. Novus Convert reads the [Events] dialogue cues locally, strips override tags to plain text, and writes any of the twelve timed-text targets.

Script metadata and the style table describe presentation rather than the cues themselves; conversion keeps timing and text and reports styling as lost, because no caption target can carry it.

Convert ASS to another format

Convert other formats to ASS