Video conversion
Convert MKV to FLAC
Updated Jul 2026
MKV is a video container that can hold video, audio, subtitles, and chapters together, while FLAC is an audio-only lossless format. Converting MKV to FLAC pulls the audio track out of the video and saves it as a standalone file. Doing this on your own computer means the video never has to leave your machine.
- Extension
- .mkv
- Type
- Video
- Typically
- High-quality video containers
- Extension
- .flac
- Type
- Audio
- Typically
- Lossless music
Convert MKV to FLAC on your own computer. Nothing uploads.
How to convert MKV to FLAC
- Open Morphjet and drag in the MKV file, or a whole folder of them.
- Choose FLAC as the output. Morphjet pulls the audio track out of the video container.
- Convert. The FLAC file is written next to your original, and nothing leaves your machine.
MKV vs FLAC: what actually changes
| MKV | FLAC | |
|---|---|---|
| What it contains | Video, audio, subtitles, and chapters together | Audio only |
| File size | Large, often a few GB for a movie | Much smaller, since only the soundtrack remains |
| Audio quality | Whatever the original track was, sometimes compressed | Lossless, but no better than the track it came from |
| Plays in | Needs a video player | Any music app or audio device |
| Metadata | Title, chapters, multiple language tracks | Basic tags like title and artist |
When to convert, and when not to
Convert MKV to FLAC when you want just the audio from a video, like a concert recording, a lecture, or a movie's isolated score, and you want to keep it in a lossless format for listening or archiving.
Keep the MKV if you still want the picture, or if the audio track inside it was already compressed when it was encoded, since pulling it into FLAC won't recover any quality that was lost earlier.
Why not just use an online converter?
Video files can be large and personal, home videos, recorded meetings, footage you'd rather not hand to a stranger's server just to pull out the audio. An online converter means uploading the whole MKV before you get your FLAC back. Converting on your own computer keeps the video, and the audio pulled from it, on your machine the entire time.
Questions
Does converting MKV to FLAC lose quality?
It depends on the audio track inside the MKV. If that track was already compressed, FLAC preserves it exactly as it is, but it can't undo the earlier compression. If the track was already lossless, the FLAC matches it exactly.
Will I lose the video when I convert to FLAC?
Yes. FLAC is audio-only, so the picture and any subtitles are dropped. You end up with just the sound.
Can I convert MKV to FLAC without uploading the file?
Yes. Morphjet runs the conversion locally on your Mac or Windows machine, so the video never travels over the internet, even for large files.
What if the MKV has more than one audio track?
Many MKVs bundle several audio tracks, like different languages or a commentary track. You choose which one to extract before converting to FLAC.
Why convert to FLAC instead of a compressed audio format?
FLAC keeps every bit of the source audio, which matters if you're archiving the sound or plan to edit it later. If you just want a small file for a phone, a compressed format may suit you better.
Morphjet converts MKV, FLAC, and 1,800+ other formats, all on your machine. Launching this July.