SubSync: Auto Subtitle Synchronization Tool Based On Audio Track

Subtitle Speech Synchronizer

SubSync, or Subtitle Speech Synchronizer, is a very handy tool that automatically synchronizes movie subtitles, so you don't have to adjust them manually. The developer provides binaries for Linux (Snap) and Microsoft Windows.

The automatic movie subtitle synchronization is done by analyzing the audio track, even if it's in a different language than the subtitle file. This is done by using dictionary files that are automatically downloaded by Subtitle Speech Synchronizer, supporting a large number of languages.

The SubSync interface only supports English and Polish languages right now though.

SubSync can also synchronize subtitles based on other subtitles that are available in other languages.

The application features auto character encoding detection, drag and drop support, as well as an easy to use user interface. Some advanced settings are also included, like max points distance, minimum speech recognition score and more, but for most uses you don't need to change anything here.

Subtitle Speech Synchronizer supports automation, by passing arguments on the command line, but the application GUI needs to run in order to perform the subtitle synchronization.

Related: Download Subtitles Via Right Click From File Manager Or Command Line With

Using Subtitle Speech Synchronizer (SubSync)

Using SubSync is quite easy, but in case you need some help getting started with this application, here is a short how-to for using it to automatically synchronize subtitles.

Start by browsing for the subtitles files you want to synchronize, by clicking on the files icon next to the Subtitles box:


Next, select the movie video file by clicking the file icon next to the References box, and select either an audio track or an existing subtitle in some other language (if available):


In case SubSync doesn't detect the correct language, make sure to change it to the correct language for both the subtitle and video files.

Now click the Start button and SubSync should start synchronizing the subtitle file with your video. This may take a while if you're syncing the subtitles with an audio track.

After the synchronization is done, click the Save button and save your new synchronized subtitle file:


Download SubSync

Here's a direct link to the SubSync Snap store page:

You may also install SubSync from the Snap store by using this command:

snap install subsync

In case your Linux distribution doesn't support snaps by default, see how to install it, or download the SubSync source.


  1. is there a way to use a command line in oder to automatize this task?

    1. SubSync supports command line arguments, but the GUI still needs too run so you can automate tasks, but not on a server.

      If you installed the snap, you can run it like this: "snap run subsync". Run "snap run subsync --help" to see the available options.

  2. Ugh... Ubuntucentric snap... Perhaps it is the reason why it is not integrating with Fedora Gnome Start Menu (I could start it via terminal only - `snap run subsync`) and why there are glitches in GUI (no icons of catalogue).

    Anyway main function of SubSync is working even in Fedora. It looks almost like magic - synchronise Polish subtitles using Spanish audio track as reference - and it works correctly!

    How it is doing it? This program is capable to transcript audio?! It could be great feature itself! I thought that only extremely proprietary solutions like Google Translate could do that...

    1. Yeah, I was quite impressed by how well it worked too. The developer mentions that "synchronization is done by listening to the audio track, translating it if necessary", using the dictionaries from That's all I could find.