Convert Matroska (MKV) to FLAC
Free online converter for Matroska (MKV) files. Lossless compression with roughly half the size of WAV. Nothing to install, no watermark, and every file is deleted automatically.
Drag and drop your files
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Upload a Matroska (MKV) file to convert it to FLAC. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About MKV and FLAC
Matroska (MKV) .mkv
Matroska: an open container that will hold almost any combination of video, audio, subtitle and chapter tracks in one file.
Good for
- Unlimited tracks — multiple languages, subtitles, chapters
- Codec-agnostic, so it holds nearly anything
- Open, well documented, and resilient to damage
Trade-offs
- Browsers will not play it natively
- Many TVs and phones refuse it — the usual reason to convert
- Being a container, contents vary wildly file to file
video/x-matroska
FLAC .flac
Lossless compression for audio. Roughly half the size of WAV, and it decodes back to the original samples exactly — nothing is approximated.
Good for
- Perfect reconstruction — identical to the source
- Around 50–60% of the size of WAV
- Full tagging, and an open royalty-free format
Trade-offs
- Still far larger than MP3 or AAC
- Not supported by every portable player or car stereo
audio/flac
MKV and FLAC side by side
| MKV | FLAC | |
|---|---|---|
| Compression | Container — any codec | Lossless |
| Transparency | Depends on codec | n/a |
| Typically used for | Archival video, multi-language releases | Archiving, high-fidelity libraries |
What changes when you convert MKV to FLAC
Only the sound is kept
This takes the audio track out of the MKV and writes it as FLAC. The picture is discarded entirely, and no conversion back will return it — keep the MKV if you still need the video.
This is a re-encode, not a repackage
Some tools can move a stream into a different container untouched when the codecs happen to line up. We do not — every job here is decoded and encoded again, so the conversion takes time in proportion to the length of the file and costs a small amount of quality even where a repackage would have been possible. In exchange the output is predictable: it plays everywhere, rather than inheriting whatever the source happened to contain.
What your FLAC will contain
The output is FLAC — which is lossless, so there is no bitrate to set — the size is decided entirely by how compressible your audio turns out to be, usually landing near half of the equivalent WAV while preserving every sample exactly.
Other Matroska (MKV) conversions
Other ways to get FLAC
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