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Aegisub – Open Source Advanced Subtitle Editor

by James 11 April 2009 8 Comments


Aegisub is a free, open source, multi platform advanced subtitle editor. It works on Windows, Linux and Mac OS X systems and supports a wide range of subtitle file formats.


Being a quite obsessed cinema fan I’m often pushed to work with subtitles, sometimes for my own personal use, sometimes for my friends, translating Italian or French subtitles to English. The program I was using for this purposes was Subtitle Workshop, a solid and simple freeware program. One of the readers of this blog, Rachel, suggested that I should try a more advanced freeware subtitle editor, Aegisub.

The first impression was very good, it supports virtually any type of subtitle file, it’s fast and reliable.


As I said, I’m into translating subtitles quite often, so the first thing I wanted to check out was the Translation Assistant. There’s not much I can say about it, just that it’s more than useful, a great tool for subtitle translators.


With Aegisub you can do almost anything you could imagine with your subtitles, even rotate the lines and make karaoke subtitles.


The program might look a little bit too complex for a not very advanced user, but the support you can get is simply awesome: you can fin a comprehensive manual, find support in the forum and even on the dedicated IRC channel.

The features list is quite impressive, just take a look:

  • Unicode in UTF-7, UTF-8, UTF-16LE and UTF-16BE encodings
  • Importing non-Unicode subtitles from over 30 different character encodings, including Shift_JIS, allowing you to resume work on any subtitles regardless of your system locale settings
  • Loading advanced Substation Alpha (.ass), Substation Alpha (.ssa), Subrip (.srt) and Plain-Text (.txt) (with actor data) subtitle formats
  • Full tag conversion from SRT to ASS
  • Multiple Undo levels
  • Powerful Automation module using the Lua scripting language to create advanced karaoke effects (including per-syllable effects, similar to AssCalc) – or any other kind of subtitles manipulation
  • Syntax highlighting
  • Fonts collector to collect all fonts used in a script into a folder
  • Opening of videos via Avisynth for true preview of subtitles using VSFilter, in any format supported by DirectShow
  • Aspect ratio overriding for anamorphic videos
  • Variable Frame Rate videos via timecodes file (v1 and v2), including exporting processed times for hardsubbing
  • Display of video coordinates under mouse and simple auto positioning support
  • Audio mode which allows you to open files in any format that your DirectShow can decode, including PCM, mp3, Ogg Vorbis, AAC, AC3 and others
  • Powerful audio timing and playback mode, including full support for karaoke manipulation
  • Functions and hotkeys easily synchronizing audio/video and subtitles
  • Time shifting and manipulation by timestamps or frame numbers (once video or timecodes are loaded)
  • Advanced find and replace with support for Regular Expressions
  • Cut/Copy/Paste subtitles via plain-text format, so it can be pasted in any plain-text editor
  • Translation assistant to easily translate subtitles to another language
  • Styling assistant to quickly pick styles for each line in subtitles
  • Styles manager that allows you to categorize subtitles styles, to make working on several projects painless
  • Keyframe navigation for fast seeking to scene boundaries
  • Several subtitles manipulation macros, such as making timing continuous or recombining double lines after Optical character recognition (OCR).
  • Highlighting of subtitles that are visible on current video frame, and a button to select those
  • Preview subtitle changes immediately by pressing Ctrl+Enter
  • Shortcut buttons to set text as bold, italic, underline, strikeout, change font or any of the 4 colors
  • Extensive manual with detailed instructions and tutorials for typesetting and program usage

Version Tested




Operating System

Windows, Linux, Mac OS X

Download link


 Open source.

Multi platform and offering a huge range of advanced features.



I have to thank Rachel for recommending this awesome open source program, it’s the heaven of any subtitles junkie. Subtitle Worksop is still OK for quick simple jobs, but Aegisub is a complete toolbox for editing and making subtitles.

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If you have any trouble with this software just leave a comment, I’ll help you out! If you know better free programs in the same category, please let me know!



  • Aegisub - Open Source Advanced Subtitle Editor | Freeware Mission « WooMovies.com said:

    […] Read the original post: Aegisub – Open Source Advanced Subtitle Editor | Freeware Mission […]

  • Ivan said:

    I have one question that has nothing to do with this post,
    Do you know any freeware that is similar to nero vision 4?Nero vision 4 is part of Nero StartSmart Essentials and it isn’ free, I use it to make DVD video , it has many useful options,
    Many thanks

  • Johnny Karp said:

    I’m not familiar with Nero Vision, but from what you say it would be a DVD authoring tool. I’d suggest DVD Styler, but there are also other free alternatives.

  • Ivan said:

    @Johnny Karp

  • rono said:

    Sublight is simple and easy to use freeware utility for downloading subtitles. It features auto subtitle find feature, manual searching, uploading new subtitles, auto updates, …just use it

  • Johnny Karp said:

    Rono, I could give you a “Contributor” account, so you could login and write your reviews directly into wordpress. Then I’ll read them and publish them. What do you say?

  • rono said:

    i feel proud that you will give tihs honor to furnish your website.i gladly accept your opinion.

  • Johnny Karp said:

    Rono, I made a “Contributor” account for you, you should receive the username and password through email in a few minutes. Then you can log in and change your password and account information and write and submit your wonderful reviews. After I take a look at each article they will be published here. Let me know if there are any problems.

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