Convert Free Lossless Audio Codec (.flac) to Matroska Video (.mkv) online for free. Fast, secure audio conversion with no watermarks or registration.
Upload your .flac file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .mkv file when it's ready.
MKV (Matroska Video) is an open-standard container that can hold virtually any audio, video, or subtitle track. Unlike most video containers, MKV natively supports FLAC audio without re-encoding — the FLAC bitstream can be copied directly into the Matroska container. This makes FLAC to MKV conversion nearly instant and completely lossless. The primary use case is packaging lossless audio alongside video tracks, subtitles, or metadata in a single Matroska file.
MKV is the preferred container for archiving high-quality video with lossless audio. Blu-ray rips, remuxes, and high-bitrate encodes frequently use FLAC audio inside MKV because it provides better compression than PCM while remaining lossless. MKV also supports multiple audio tracks, so FLAC can sit alongside a lossy AAC track for devices that do not decode FLAC. Additionally, MKV's chapter and attachment support allows embedding cover art, fonts, and navigation metadata.
FFmpeg uses stream copy (-c:a copy) to remux FLAC audio into an MKV container without re-encoding. The FLAC codec is natively supported by Matroska (codec ID A_FLAC). MKV's EBML (Extensible Binary Meta Language) structure allows arbitrary numbers of audio, video, and subtitle tracks with per-track language tags. Chapter markers use the Matroska Chapters specification. The muxing operation is near-instant since no transcoding occurs.
Zero quality loss when using stream copy mode. The FLAC audio data is transferred bit-for-bit from the FLAC container to the MKV container. The same PCM samples are preserved exactly.
| Device | FLAC | MKV |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Native | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Resolution: N/A
Bitrate: 256 kbps
AAC format required
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
FLAC to MKV conversion is ideal for media archivists and home theater enthusiasts who want lossless audio in a flexible multimedia container. The conversion is instant and lossless when using stream copy.
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Funguje všude
Jakýkoli prohlížeč, jakékoli zařízení
| No |
| Vlastnost | FLAC | MKV |
|---|---|---|
| Celý název | Free Lossless Audio Codec | Matroska Video |
| Přípona | .flac | .mkv |
| Nejlepší pro | Lossless compression | Multiple audio tracks |