Convert MKV to ALAC — Free Online Converter

ALAC (Apple Lossless Audio Codec) compresses audio to roughly half its original size without losing a single bit of data. Converting MKV to ALAC extracts the audio and wraps it in an M4A container that Apple devices, iTunes, and Apple Music handle natively, making it the ideal lossless format for the Apple ecosystem.

If you own an iPhone, iPad, Mac, HomePod, or Apple TV and want lossless audio from your MKV video files, ALAC is the only lossless codec guaranteed to play on all Apple hardware without third-party apps. FLAC, by comparison, requires apps like VLC on iOS and is not supported by Apple Music or iTunes for library management.

ALAC also provides meaningful storage savings over uncompressed formats. A typical CD-quality audio track compresses from 10 MB/minute (AIFF/WAV) down to about 5-6 MB/minute in ALAC, saving roughly 40-50% of disk space while remaining mathematically identical to the original when decoded. For users with large music libraries extracted from MKV concert recordings, this savings adds up significantly.

FFmpeg decodes the MKV audio stream (any codec) and re-encodes to ALAC using the native alac encoder. The output is packaged in an M4A (MPEG-4 audio) container. ALAC supports sample rates up to 384 kHz, bit depths up to 32-bit, and channel counts up to 7.1 surround. Compression ratios typically range from 40-60% of the original PCM size depending on the audio content's complexity.