The quickest way to delete subtitles from an MKV file

You can remove subtitle tracks from an MKV file using mkvtoolnix, a free tool that edits MKV containers without re-encoding the video or audio. Open the file in mkvtoolnix's GUI, uncheck the subtitle tracks you want to remove, and save. The process takes a few minutes and produces a new file with those tracks stripped out. If you prefer command-line tools, ffmpeg or mkvmerge (part of mkvtoolnix) can do the same thing with a single command.

The reason you need a specialized tool is that MKV files are containers — they hold video, audio, and subtitle streams bundled together. Simply deleting a subtitle file won't work because the subtitles are embedded inside the MKV. You need software that can read the container, identify which tracks to keep, and write a new file with only those tracks.

Key Takeaways

  • mkvtoolnix is free, works on Windows, Mac, and Linux, and lets you see all subtitle tracks before removing them.
  • The GUI method takes about five minutes: open the file, uncheck subtitle tracks, click "Start muxing", and wait for the new file.
  • Command-line tools like mkvmerge or ffmpeg are faster if you need to process many files at once.
  • Removing subtitles does not re-encode video or audio, so the output file is the same quality as the original.
  • The original file stays unchanged; the tool creates a new file with your changes.

Using mkvtoolnix GUI on Windows, Mac, or Linux

Download mkvtoolnix from the official site (mkvtoolnix.download). Install it, then open the program and click "Add source files". Select your MKV file. The GUI will show you every track in the file — video, audio, and subtitles — in a list on the left side.

Find the subtitle tracks in that list. They are usually labeled "Subtitle" or "S_TEXT/UTF8" or "S_TEXT/ASS". Uncheck the box next to each subtitle track you want to remove. Leave the video and audio tracks checked. At the bottom of the window, set an output filename (the program suggests one automatically). Click "Start muxing" and wait. The tool will create a new MKV file without those subtitle tracks. The original file is not changed.

The time this takes depends on file size, but for most files under 5 GB it finishes in under a minute. mkvtoolnix does not re-encode anything, so it is much faster than video conversion software.

Removing subtitles with mkvmerge from the command line

If you are comfortable with a terminal, mkvmerge (which comes with mkvtoolnix) can remove subtitles in one line. Open a terminal or command prompt and navigate to the folder where your MKV file is. Run this command, replacing input.mkv with your filename and output.mkv with what you want to call the new file:

mkvmerge -o output.mkv --no-subtitles input.mkv

The --no-subtitles flag tells mkvmerge to drop all subtitle tracks. If you want to keep some subtitles and remove only specific ones, use -s followed by the track number. For example, to keep only audio track 0 and video track 1 and remove everything else:

mkvmerge -o output.mkv -v 1 -a 0 input.mkv

Run the command and wait for it to finish. The new file will be in the same folder.

Using ffmpeg to strip subtitles

ffmpeg is a more general-purpose tool that can handle many video formats, not just MKV. If you already have ffmpeg installed, you can use it to remove subtitles without installing anything else. The command is:

ffmpeg -i input.mkv -c copy -sn output.mkv

The -c copy flag tells ffmpeg to copy the video and audio without re-encoding. The -sn flag means "no subtitles". This produces the same result as mkvmerge but works with more container formats if you ever need it.

ffmpeg is slower to start than mkvmerge but the actual processing speed is similar. The main reason to use ffmpeg is if you are already familiar with it or if you need to do other things to the file at the same time (like change the audio language or remove specific audio tracks).

What happens if you want to keep some subtitles but remove others

In mkvtoolnix GUI, simply uncheck only the subtitle tracks you want to remove and leave the others checked. The program will keep the ones you checked and drop the rest.

From the command line with mkvmerge, identify which subtitle track number you want to keep. Run mkvmerge --identify input.mkv to see all tracks and their numbers. Then use the -s flag with that number:

mkvmerge -o output.mkv -s 2 input.mkv

This keeps only subtitle track 2 and removes all others. You can list multiple tracks: -s 2,3 keeps tracks 2 and 3.

Why the output file is sometimes larger or smaller

When you remove subtitle tracks, the output file is usually smaller because you are removing data. However, the difference is often small — subtitles are text and take up far less space than video or audio. A file with multiple subtitle tracks might be only 50 to 200 MB larger than one without them, depending on how many languages are included.

Occasionally the output file is slightly larger than the input, usually by a few megabytes. This happens because mkvtoolnix or ffmpeg rewrites the container structure, and the new structure may have different padding or metadata layout. This is normal and not a sign of a problem.

Frequently Asked Questions

Can I undo this if I remove the wrong subtitles?

No — the original file is not changed, but the new file you created has the subtitles removed permanently. Keep the original file as a backup. If you made a mistake, you can always run the tool again on the original and uncheck different tracks.

Will removing subtitles affect video or audio quality?

No. These tools copy the video and audio streams without re-encoding them. Only the subtitle tracks are removed. The video and audio quality stays exactly the same.

What if the file has subtitles in multiple languages?

mkvtoolnix shows each language as a separate track. You can uncheck all of them to remove every subtitle, or uncheck only the ones you do not want and keep the rest. The GUI makes it easy to see which language each track is.

Do I need to install anything besides mkvtoolnix?

No. mkvtoolnix includes everything you need. It is a single download and install. ffmpeg is separate and requires its own installation, but mkvtoolnix works on its own.

How do I know which track number is which subtitle?

In mkvtoolnix GUI, hover over a subtitle track in the list — it shows the language and encoding. From the command line, run mkvmerge --identify input.mkv and look for lines that say "subtitles" — the number at the start of each line is the track number.