Subtitles, resynch'ed.

Professional grade subtitle tools. Shift, Resync, Convert, Clean all your subtitles.


Format: hours : minutes : seconds , milliseconds


  • 2020.06.21

    [NEW] Timecode shifting added! You can now resynchronize using the first and last timecode. Thanks Wally!

  • 2020.06.07

    [NEW] New UTF-8 encoding tool added.

  • 2020.05.31

    [NEW] New design. New conversion tool. New cleaning tool. Now supports .vtt files. All files are now truly encoded in UTF-8.

  • 2020.05.11

    [FIXED] Carriage returns being skipped in .srt files. Thanks Johnny!

  • 2018.01.15

    [FIXED] Incorrect time shifting when using decimals. Thanks Benjamin!

  • 2017.11.28

    [ADDED] Filesize limit increased.

  • 2017.11.15

    [FIXED] Line feeds being skipped in .srt files. (currently monitoring) Thanks Yvonne!

Professional-Grade Subtitle Tools

4.8 out of 5 stars - 28639 votes

SubSyncer is a Professional-Grade free online tool able to resync/shift/convert/clean subtitles in any languages, in any formats. With SubSyncer you can:

Ease of use & Flexibility. All featured subtitle tools support all below subtitle file formats:

  • .srt
  • .vtt
  • .txt
  • .ass
  • .ssa
  • .sub
  • .sub (MicroDVD)
  • And more coming...

Subtitle Re-Synchronization

What is subtitle re-synchronization?

Subtitle re-synchronization is the fact to re-align subtitles (dialogue cues) with a video.

Subtitles can be found out of sync due various reasons. It can be due to the number of frames per second (FPS) of a video or it can be due to the video being longer or shorter.

How to re-synchronize subtitles?

There are a couple of different ways to resynchronize subtitles. You can resynchronize by:

  • Time shifting (linear shift), using VLC or this tool.
  • FPS to FPS shifting (gradual shift) using this tool.

SubSyncer can shift all your cues by time and by FPS in just one click.

Subtitle Time Shifting

What is subtitle time shifting?

Subtitle time shifting is the fact to move all subtitles (dialogue cues) by a certain time.

There are many reasons for such issue. This may be due to the video being cut shorter or made longer.

How to time shift subtitles?

There are a couple of different ways to time shift subtitles. You can do it by following one of the methods below:

  • Using VLC: Press G to add a 50 milliseconds delay or press H to remove 50 milliseconds delay (fasten).
  • You can use SubSyncer's shifting tool to permanently shift your subtitles.

All subtitle tools in one click


Subtitles are slowly becoming out of sync?
This is due to the number of frames per second (FPS) of videos that will result in subtitles become slightly delayed over time.
This tool gets the FPS of the original subtitle file and changes all cues' timings according to your video's FPS.

Supported formats: ALL (.srt,.vtt,.txt,.ass,.ssa,.sub)

Time Shift

All cues are out of sync by the same interval?
This may be due to your video being cut shorter or longer at some places.
This tool can shift all cues by the same time interval at once. You can choose to fasten or delay all cues in milliseconds, and shift the subtitles until it fits your video.

Supported formats: ALL (.srt,.vtt,.txt,.ass,.ssa,.sub)


Different video players support different file formats.
Or it could be that you want more flexibility using one format over another.
SubSyncer's conversion tool can convert your subtitle files to your desired format. When possible, it will automatically translate all cue syntaxes to fit the new file format!

Supported formats: ALL (.srt,.vtt,.txt,.ass,.ssa,.sub)


Syntaxes are specific to subtitle file formats.
Some files may have wrong syntaxes or may include closed captions.
SubSyncer's cleaning tool allows you to remove all syntaxes that may not be suitable or that you do not want (ex: Closed Captions). You can decide what to keep or what to remove.

Supported formats: ALL (.srt,.vtt,.txt,.ass,.ssa,.sub)

Frequently Answered Questions

How to resynchronize subtitles in VLC?

There are 3 ways to temporarily synchronize your subtitle in VLC media player.
Method 1:
  • Press G to add a 50 milliseconds delay
  • Press H to remove 50 milliseconds delay (fasten)
Method 2: (source)
  1. Press Shift+H when you hear a specific sentence
  2. Press Shift+J when this sentence appears in the subtitles
  3. Press Shift+K to resynchronize the subtitles by the time difference between steps 1 and 2
You can also interchange Steps 1 and 2 if your subtitles are faster than the voices.

Method 3:
  1. In VLC, go to Tools > Track Synchronization
  2. In Subtitles/Video adjust the delay by clicking on the arrows up or down. You can fasten or delay the subtitles accordingly.
As those methods are not permanent, you can then use SubSyncer to permanently fix your subtitles with the correct timings.

How to convert subtitles to another format?

Subtitle formats can be very different from one another. This is due to many subtitle formats being developed over the years by different teams to answer different needs.
In order to convert subtitles from one format to another, you can use any of the solutions below: However, if you do not want to download a software and just want to have your subtitle converted now, you can just use SubSyncer’s conversion tool.

About SubSyncer

This was originally a personal project that originated from my own need in having such tools without downloading any software. I decided to make it public and free of use so that everyone can enjoy this tool.
I am always looking to improve the website/algorithm further so if you have any problem, feedback or suggestion please send me an e-mail. I will answer within 48 hours.

About SubSyncer

Privacy and
Personal Informations

This website does not record any browsing informations. Subtitle files are uploaded upon submission and temporarily saved for 60 days on the server. Files will not be shared with other third-parties and may only be used to improve this tool's accuracy.