MKV to FLAC Converter — Free, Online, No Upload

MKV files often carry high-quality audio tracks — lossless PCM, DTS-HD, or TrueHD — that are completely inaccessible outside of a media player like VLC or Plex. If you want to archive that audio, run it through audio analysis software, or add it to a lossless music collection, the MKV container stands directly in the way.

FLAC (Free Lossless Audio Codec) is the open standard for lossless audio. It compresses without any quality loss — every bit of the original audio is preserved and can be reconstructed exactly. FLAC is supported in Plex, Jellyfin, Kodi, foobar2000, Audirvana, and virtually all serious audiophile and archival software. It is the format of choice for music libraries where quality cannot be compromised.

When you extract audio from MKV to FLAC, the output quality is exactly what was in the MKV — no more, no less. If the source audio is already lossless PCM (common in Blu-ray rips), you get a perfect copy in a portable, indexed format. If the source is a lossy codec like AC3 or AAC, converting to FLAC preserves that lossy signal without any additional degradation — but does not restore what the original compression removed. FLAC files are large compared to lossy formats but significantly smaller than raw WAV.

Typical sizes: MKV 200–800 MB (1 minute 1080p); FLAC 20–40 MB (3-minute song).

FLAC will not restore detail the MKV encoder removed, and the file gets bigger.