Convert MP4 to FLAC — Free Online Converter

MP4 to FLAC conversion extracts the audio track from an MPEG-4 video and encodes it as a Free Lossless Audio Codec file. FLAC is the most widely supported open-source lossless audio format, compatible with Android, Windows, Linux, most car stereos, and a growing number of Apple devices (since iOS 11). Unlike lossy formats, FLAC compresses audio without discarding any data, achieving 40-60% size reduction compared to raw PCM.

Our converter decodes the audio from your MP4 and re-encodes it with the reference FLAC encoder. Metadata including title, artist, and album can be carried through if present in the source file.

FLAC is the standard for lossless audio outside the Apple ecosystem. Audiophiles, music producers, and archivists choose FLAC for its perfect fidelity, open-source nature, and universal support. Extracting audio from video as FLAC ensures you have the highest quality master for future use — you can always transcode FLAC to MP3 or AAC later without going back to the video file. Streaming services like Tidal and Amazon Music HD use FLAC for their lossless tiers.

FFmpeg decodes the MP4 audio stream and feeds PCM samples to the FLAC encoder. Compression level defaults to 5 (on a 0-8 scale), balancing encoding speed with file size. Higher levels (7-8) produce slightly smaller files but take significantly longer. FLAC supports up to 32-bit depth and 655,350 Hz sample rate, though typical output is 16-bit or 24-bit at 44.1 or 48 kHz. The FLAC container stores Vorbis comments for metadata and supports embedded album art.