Converting M4A to FLAC wraps the decoded audio in a lossless compressor. The main reason to do this is library management: unifying a mixed format collection under FLAC, or feeding tools that handle FLAC metadata more cleanly than M4A.
Drag & drop audio files here, or browse
Drop your M4A files here
No audio change. Starting from lossy M4A means the FLAC preserves lossy audio exactly; you don't gain quality, just a different container format. The FLAC file will be several times larger than the M4A.
FLAC plays on Windows, macOS, Linux, Android, modern iOS, and every major library or player. It's well-supported by music server software.
M4A is an MPEG-4 container that almost always holds AAC audio (though it can hold ALAC too). The payload is identical to what's inside an .aac file; the difference is that M4A carries proper tags, chapter markers, and cover art. iTunes, Apple Music, and iOS write M4A by default.
FLAC is a lossless compressor: it shrinks PCM audio to roughly 50–60% of its original size and decodes back to a bit-perfect copy. It supports tags, cue sheets, and up to 32-bit / 655 kHz, which makes it the de facto format for CD rips and audiophile music libraries.
The FLAC container is lossless relative to its input. But the input came from a lossy M4A, so the audio inside the FLAC is lossy. FLAC preserves it perfectly; it doesn't restore what M4A threw away.
Library consistency. Some music server software handles FLAC better than M4A for things like ReplayGain, cover art, and tagging. If your tooling specifically wants FLAC, this gets you there.
M4A is an MPEG-4 container that almost always holds AAC audio (though it can hold ALAC too). The payload is identical to what's inside an .aac file; the difference is that M4A carries proper tags, chapter markers, and cover art. iTunes, Apple Music, and iOS write M4A by default.
FLAC is a lossless compressor: it shrinks PCM audio to roughly 50–60% of its original size and decodes back to a bit-perfect copy. It supports tags, cue sheets, and up to 32-bit / 655 kHz, which makes it the de facto format for CD rips and audiophile music libraries.
Yes. The converter runs entirely in your browser using FFmpeg compiled to WebAssembly. Your audio files are never uploaded, never sent to a server, and never leave your device.
There's no hard limit, but because everything runs in your browser you're bounded by available memory. Files over about 2 GB total can get slow or hit browser memory limits. Process in smaller batches if you run into issues.