About SUBtools

SUBtools is primarily designed to be a helper-application for MP4toolsMKVtools, and AVItools. Subtitle files can be sent to it from any of these three applications for quck editing and then sent back for incorporation into a processed video. If desired, it can also be used as a light-weight standalone subtitle editor. SUBtools is a part of the VIDEOtoolbox suite of applications so if you already have a VIDEOtoolbox registration code, you can immediately get started editing subtitles. 


  • Opens the most common text-based subtitles (SRT and SSA/ASS)
    • Export to SRT or ASS format
    • Can automatically fix common timing conflicts and formatting errors.
    • Can edit subtitle times individually (i.e., line by line) or for all lines of dialog (shift or stretch).
    • Can automatically delete unwanted dialog formatting
    • Edit SSA/ASS styles
    • Can filter subtitles using SSA/ASS styles
    • Video preview SSA/ASS formatting
  • Opens the most common graphical subtitles (Vobsub and PGS)
    • Uses OCR (Tesseract) to convert to SRT format.
    • Can edit for corrections as the subtitle is being converted
    • Can use localized dictionaries.
  • Can transfer subtitle to/from  MP4tools, MKVtools, and AVItools.
  • Automatically reformats SSA and ASS subtitles to the correct SRT format.

System Requirements

SUBtools is Intel-only and requires Mac OS X 10.7.x or later.  It has been tested on a MacBook Pro and a Mac Pro with no known issues.


A big thank you to Simone Pizzuti for coming up with the new and improved icon for SUBtools. If you like the result and are looking for a graphic designer or web designer, you can contact Simone at s.pizzuti@chromaticastudio.com.