M4A to FLAC Converter
Convert M4A to FLAC free — no upload, no signup
To convert M4A to FLAC, drop your M4A audio files into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. Store M4A audio in FLAC for systems that require it.
Drop audio files here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
FLAC is lossless — no bitrate to choose. Sample rate and channels are under Advanced.
Advanced
How to convert M4A to FLAC
Add your M4A files
Drag and drop M4A files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Check the settings
FLAC is lossless, so there's no bitrate to pick. Change sample rate or switch to mono under Advanced if a device needs it.
Convert and download
Click Convert, then download each FLAC file or all of them as one ZIP.
Why convert M4A to FLAC?
Some music servers and archive workflows only accept FLAC.
What happens when you convert M4A to FLAC?
AAC M4As are decoded and stored losslessly as FLAC, which is much larger. If your M4A uses Apple Lossless (ALAC), the FLAC is a true lossless copy.
How does Fylo convert M4A to FLAC?
Fylo decodes the AAC (or ALAC) audio in the M4A with ffmpeg compiled to WebAssembly and encodes it with FLAC lossless compression. Nothing is added back: the FLAC is an exact but larger copy of the decoded M4A (≈ 18–24 MB for a 3-minute song versus ≈ 3.6 MB at 160 kbps). The original sample rate and channel layout are kept unless you change them under Advanced.
What's the difference between M4A and FLAC?
M4A is an MPEG-4 container that holds only audio — usually AAC, or Apple Lossless (ALAC). Apple popularised the extension with the iTunes Store in 2003; iPhone Voice Memos and many podcasts also use it. Audiobooks often use the related .m4b extension.
FLAC (Free Lossless Audio Codec) was released in 2001 and later maintained by the Xiph.Org Foundation. It compresses PCM audio like a ZIP file compresses data: nothing is thrown away, so a FLAC decodes to exactly the same samples as the source WAV, typically at 50–70% of the size.
Learn more: M4A format guide · FLAC format guide
| Property | M4A | FLAC |
|---|---|---|
| Compression | Lossy (AAC) or lossless (ALAC) | Lossless |
| Typical bitrate | 128–256 kbps | ≈ 700–1,100 kbps |
| 3-minute song | ≈ 3.6 MB at 160 kbps | ≈ 18–24 MB |
| Tags and cover art | Yes (full, with cover art) | Yes (with cover art) |
| Compatibility | Apple devices, Android, Windows 10+, browsers | Android, Windows 10+, macOS, most players and hi-fi gear |
| Best for | iTunes/Apple Music libraries, voice memos, audiobooks | Archiving music without quality loss |
| Introduced | 2003 | 2001 |
Frequently asked questions
Is ALAC to FLAC lossless?
Yes — both are lossless, so the audio is identical.
Does converting AAC M4A to FLAC improve quality?
No. AAC M4A is lossy, so detail removed during its compression can't be restored. The FLAC is a lossless copy of what the AAC M4A sounds like — bigger, but not better.
Is my M4A file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your M4A file is read directly from your device and never sent anywhere.
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