How to Sync Your Subtitles Automatically with SubSync

Autofix Subtitles With Subsync Featured

If your entertainment horizons extend beyond your own language, you know that only a select few foreign movies and series end up dubbed. For the rest, you have to rely on subtitles. Unfortunately, the vast majority of subtitles are created by hobbyists, based on their version of a video that could be different than yours. Thus, they wouldn’t play in sync with your video.

Until recently, you would either have to find different subtitles, wait for someone to create one, or synchronize them yourself. Now, smart tools like SubSync (Subtitle Speech Synchronizer) can do it automatically in less than five clicks. Let’s see how.

SubSync is cross-platform compatible and can be used on Windows, macOS and Linux. We will be using Linux (Ubuntu) for this article.


If using an Ubuntu-compatible distribution, you will find SubSync in its Software Center. Alternatively, you can install it in a terminal with the following command:

sudo snap install subsync
Autofix Subtitles With Subsync Install

After it’s installed, launch the program and also open your favorite file browser, pointing it to the folder with your video and problematic subtitles.

Find more subtitles

Even if you can’t find adequately synchronized captions for your language, it’s worth doing a quick search to see if you can find some highly rated ones in other languages. If you do, download them.

Autofix Subtitles With Subsync Subs Loaded

Even if you don’t understand their language, if you find synchronized subtitles, SubSync will be able to use them as a reference for syncing yours.

Add the unsynchronized subs

Place SubSync and your file manager windows next to each other. Choose the file of the problematic subtitles that are in your language that you would like to fix and drag and drop it to the “Subtitles” field of SubSync.

Autofix Subtitles With Subsync Unsyced

In almost all cases, your subtitles will only have a single stream, so the only thing you will have to do in the window that pops up is select your language from the pull-down menu, then click OK.

Autofix Subtitles With Subsync Streams

Reference subs or video

If you found synchronized subtitles in a different language to use as a reference, drag and drop that file to the “References (video or other subtitles)” field of SubSync.

Autofix Subtitles With Subsync Reference File

If you didn’t, use the video itself instead. SubSync will be able to analyze its audio and map any speech patterns it detects to the subtitles. Since this is somewhat slower, if available, opt to us subtitles in a foreign language as a reference.

Autofix Subtitles With Subsync Reference Language

As before, set your language in the window that pops up and click OK.

Start the sync

With the two files selected, the only thing that remains is a click on “Start” for the process to begin.

Autofix Subtitles With Subsync Begin

Depending on the language you chose, SubSync will inform you that it needs to fetch some new assets. Accept their download.

Autofix Subtitles With Subsync Download Assets

The downloaded file will be relatively small, so you won’t have to wait more than a few seconds.

Autofix Subtitles With Subsync Speech File

Please do note, though, that it is for a specific language. If you choose a different language in the future, SubSync will prompt you again to download more speech recognition models.

Sync Points

When syncing your subtitles, SubSync tries to find matching points in either the foreign-but-synchronized subtitles or the video you’re using as a reference. The more points it finds, the more accurate the results.

Autofix Subtitles With Subsync Sync Points

When it thinks it has found enough syncing points, SubSync will inform you that you can save the subtitle. For better results, wait for the process to fully complete to find all possible syncing points.

In case of failure

Sometimes the process might fail. In our case, we used a short video, and SubSync couldn’t find enough synchronization points. When this happens, it’s time to pay a visit to the program’s options.

Autofix Subtitles With Subsync Failed

Click on the button with the three dots and choose “Settings.”

Autofix Subtitles With Subsync Menu Settings

We can’t suggest a single tweak that could fix all subtitle problems since each case is different.

We fixed our problem by reducing the number of “Min points no” to 15.

Autofix Subtitles With Subsync Min Points

In other cases, you could try increasing the “Max points distance” or decreasing the “Min words similarity” and “Min speech recognition score” to reduce the syncing accuracy.

Autofix Subtitles With Subsync Down To 15

It would be best if you tried this as a last resort since, in many cases, those tweaks lead to suboptimal results.

Check and rename

When the process completes successfully, save the new, synchronized subtitle file in your videos’ folder.

Autofix Subtitles With Subsync Great Success

Open your video in your favorite media player and load your new subtitle over it. Barring the rare fluke, the audio and text will match.

Autofix Subtitles With Subsync Test Subs

If you’re happy with the results, delete the older, problematic version of the subtitles and rename the new file so that it has the same name as the video – minus its extension.

Autofix Subtitles With Subsync Rename File

This way, most media players will “understand” it is a subtitle file for the specific video and auto load your subtitles when you open it.

Odysseas Kourafalos
Odysseas Kourafalos

OK's real life started at around 10, when he got his first computer - a Commodore 128. Since then, he's been melting keycaps by typing 24/7, trying to spread The Word Of Tech to anyone interested enough to listen. Or, rather, read.

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