Add your MKV file
Drop one or more .mkv files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
MKV to FLAC
Pulling the soundtrack out of a .mkv video into .flac audio keeps what you can hear and drops the picture entirely. Free, private, and validated — the file never leaves your browser.
100% private for supported formats
Runs on your deviceConvert supported files
Drop MKV files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Matroska video to FLAC audio
Pulling the soundtrack out of a .mkv video into .flac audio keeps what you can hear and drops the picture entirely. An .mkv file uses the Matroska container, an open format designed to hold an unlimited number of video, audio, and subtitle tracks in one file. Collectors of high-quality rips and archival copies favor .mkv because it keeps every language track, chapter marker, and font attachment together.
A .flac file contains audio compressed with the Free Lossless Audio Codec, which shrinks recordings without discarding a single sample. Decoded .flac output is bit-identical to the source, so the format has become the standard for music archiving and high-resolution downloads. For this route the practical draw is genuinely lossless while roughly halving storage and open specification with no royalties anywhere in the chain — balanced against still several times larger than a good lossy encode, which is worth knowing before you commit a large batch.
Why convert MKV to FLAC?
The usual reason to take .flac audio out of a .mkv file is that only the sound matters — a talk, interview, song, or podcast segment. Keeping the video stream would waste storage, and a dedicated audio file is easier to trim, tag, and play. On the source side, safari and iOS refuse the container outright; on the target side, the payoff is genuinely lossless while roughly halving storage, which is exactly what you want for ripping CD collections for permanent archival.
MKV vs FLAC at a glance
| Aspect | Matroska video (.mkv) | FLAC audio (.flac) |
|---|---|---|
| Format type | Container — quality depends on the codecs and settings inside | Lossless — every pixel or sample is preserved exactly |
| How it stores data | built on EBML, a binary XML-like structure that lets the container gain features without breaking older parsers | linear prediction followed by Rice coding typically yields files 40 to 60 percent the size of raw PCM |
| Strongest at | archiving discs while preserving every audio track and subtitle stream | ripping CD collections for permanent archival |
| Weak spot | safari and iOS refuse the container outright | still several times larger than a good lossy encode |
| Metadata | matroska tags cover title, cast, and arbitrary key-value pairs, and the container can embed cover art and other files as attachments | vorbis comments for tags plus a dedicated PICTURE block for cover art; cue sheets can be embedded for whole-disc rips |
Pick FLAC as the output
Select .flac in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if FLAC is selectable, the route is real and validated.
Convert on your device
Press Convert. A WebAssembly FFmpeg build demuxes the audio track and re-encodes it locally; the video stream is simply discarded.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid FLAC file. Outputs keep the original filename with the .flac extension.
MKV to FLAC questions, answered
Will converting MKV to FLAC lose quality?
Since mkv is container-oriented and flac is lossless-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .flac itself requires.
Is it private to convert MKV files here?
Yes — the .mkv file is processed inside your browser tab and never uploaded. A WebAssembly FFmpeg build demuxes the audio track and re-encodes it locally; the video stream is simply discarded. Close the tab and the file is gone from memory.
Where will the FLAC file work?
All major browsers decode .flac, Windows 10 and later plus Android play it natively, and virtually every dedicated audio player supports it. The persistent gap is Apple's Music ecosystem, where converting to ALAC delivers the same audio in a supported wrapper.
Will the FLAC file be bigger or smaller than my MKV?
Much smaller — the video stream is usually 80–95% of a .mkv file's weight, and it is discarded entirely. The remaining audio is re-encoded at the bitrate implied by your quality setting.
What happens to the metadata in my MKV file?
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, matroska tags cover title, cast, and arbitrary key-value pairs, and the container can embed cover art and other files as attachments; none of it is transmitted anywhere because the file never leaves your browser.