Video conversion
Convert MKV to MP3
Updated Jul 2026
MKV is a video container that can hold video, audio, and subtitles together, and MP3 is a plain audio file that plays anywhere. To convert MKV to MP3, open the file in a converter and pull out just the audio track. Doing it on your own computer means the video never has to be uploaded anywhere to get the sound out of it.
- Extension
- .mkv
- Type
- Video
- Typically
- High-quality video containers
- Extension
- .mp3
- Type
- Audio
- Typically
- The universal audio format
- Compression
- Lossy
Convert MKV to MP3 on your own computer. Nothing uploads.
How to convert MKV to MP3
- Open Morphjet and drag in the MKV file, or a whole folder of them.
- Choose MP3 as the output format. Morphjet pulls the audio track out and leaves the video behind.
- Convert. The MP3 is written next to your original, and nothing leaves your machine.
MKV vs MP3: what actually changes
| MKV | MP3 | |
|---|---|---|
| Contains video | Yes | No, audio only |
| File size | Large, often gigabytes | Much smaller, tens of megabytes |
| Audio quality | Whatever the source track was, often high | Good, but compressed and lossy |
| Opens everywhere | No, needs a compatible video player | Yes, universal support |
| Multiple audio tracks or subtitles | Yes, can hold several of each | No, one audio track only |
| Keeps title and artist tags | Sometimes, in container metadata | Yes, as ID3 tags if present |
When to convert, and when not to
Convert MKV to MP3 when you only want the audio, like a concert recording, a lecture, a movie's commentary track, or a song ripped from a music video, and you don't need the picture at all.
Keep the MKV if you still want to watch the video, since converting to MP3 throws the picture away for good.
Why not just use an online converter?
MKV files are often large recordings, whether that's a downloaded show, a screen capture, or something personal, and an online converter needs you to upload the whole thing just to hand back a small audio file. Converting on your own computer means that video never leaves your machine, only the finished MP3 does anything, and that's just sitting on your drive.
Questions
Does converting MKV to MP3 lose quality?
The audio itself is compressed when it becomes MP3, so there's some quality loss, though at a reasonable bitrate it's hard to notice for speech or casual listening. The bigger change is that you lose the video entirely, since MP3 can't hold it.
What happens to the video when I convert MKV to MP3?
It's discarded. MP3 is an audio-only format, so converting just extracts the sound and leaves the picture behind. If you might want the video later, keep a copy of the original MKV.
Will the MP3 keep the title, artist, or other tags?
If the MKV has that information stored in its metadata, Morphjet carries it over into the MP3's ID3 tags where it can. Not every MKV has clean tags to begin with, since it depends on how the file was made.
Can I convert MKV to MP3 without uploading the file?
Yes. Morphjet runs the conversion on your own computer, so a large MKV never has to travel over the internet just to get the audio out of it. It works the same with your wifi off.
Why is the MP3 so much smaller than the MKV?
Most of an MKV's size is video, and video takes up far more space than audio. Once the picture is dropped and the audio is compressed into MP3, what's left is a fraction of the original file.
Morphjet converts MKV, MP3, and 1,800+ other formats, all on your machine. Launching this July.