Convert M4A to FLAC
Convert M4A audio files to FLAC format directly in your browser. FLAC is the open lossless container used by Bandcamp, Qobuz, Roon, and audiophile music libraries. Stops further generational loss after a single decode. No upload needed.
Drag 'n' drop files here, or
click to select files
.m4a
Drop your files and click Convert to get FLAC
//when_to_use
When to Convert M4A to FLAC
- Migrating iTunes M4A libraries to FLAC for import into Roon (which prioritizes lossless for DSP, room correction, and metadata enrichment)
- Converting M4A purchases to FLAC for re-upload to Bandcamp's lossless tier (which accepts FLAC, ALAC, WAV)
- Preparing M4A field recordings as FLAC for long-term archival in DAM systems and broadcast libraries
- Decoding M4A audiobook chapters to FLAC before re-editing — avoiding compounded AAC artifacts on every save in Audacity
- Migrating M4A tracks to FLAC for sync to high-end DAPs (Astell&Kern, FiiO, HiBy) that often de-prioritize lossy
//comparison
M4A vs FLAC
| Property | M4A | FLAC |
|---|---|---|
| Compression | Lossy (AAC LC) | Lossless (FLAC level 5) |
| Typical size (3 min) | 3-5 MB | 18-25 MB |
| Future generational loss | Yes (re-edits compound) | None |
| Patent / royalty | Licensed (Fraunhofer) | Open, royalty-free |
| Audiophile player priority | De-prioritized | Native, prioritized |
| Best for | iTunes, iPhone playback | Roon, Qobuz, lossless archival |
//how_it_works
How It Works
Drop your M4A files
Drag and drop or pick M4A files. First conversion loads FFmpeg WASM (~30MB).
FFmpeg decodes AAC
FFmpeg WASM walks the MP4 atom tree, extracts the AAC stream, and decodes to 16-bit PCM at the source sample rate.
FLAC encode (level 5)
PCM is re-encoded with FFmpeg's FLAC encoder at compression level 5 — lossless, with stream info and metadata block headers.
Download FLAC files
FLACs import into Roon, JRiver, Plex, Audirvana, Foobar2000, and every modern audiophile library.
// under the hood
M4A wraps AAC (lossy psychoacoustic) inside MP4. FLAC (Free Lossless Audio Codec) is the Xiph.Org open lossless format — typically 50-60% the size of uncompressed PCM with bit-perfect reconstruction. Our converter uses FFmpeg WASM to demux the MP4, decode AAC to 16-bit signed PCM, then re-encode with FFmpeg's FLAC encoder at compression level 5 (the FLAC default).
//faq
Frequently Asked Questions
- Will FLAC restore the quality lost by AAC?
- No. The detail discarded by the AAC encoder is gone forever. FLAC will be a bit-identical lossless copy of the AAC's decoded PCM — no better than the source. Use FLAC to stop further loss in future re-edits, not to recover what's missing.
- So why bother converting M4A to FLAC?
- Three reasons: (1) audiophile players (Roon, JRiver, Audirvana) refuse or de-prioritize lossy formats — FLAC unlocks DSP, EQ, and album-aware playback; (2) some libraries (Bandcamp lossless tier, Qobuz uploads) reject AAC; (3) once in FLAC, you can re-edit, splice, or remaster without compounding lossy artifacts.
- How big will the FLAC be vs the M4A?
- FLAC is lossless compressed — typically 50-60% the size of uncompressed PCM but 3-5x larger than the M4A. A 4 MB M4A song often becomes a 18-25 MB FLAC. If size matters more than archival quality, OGG or AAC are better targets.
- What FLAC compression level do you use?
- We encode with FFmpeg's FLAC encoder at compression level 5, the FLAC default. Output is 16-bit signed PCM at the source sample rate (44.1 or 48 kHz), preserving the input channel count. Level 5 balances encode speed and final size — higher levels save only 1-2% more.
- Are my files uploaded?
- No. FFmpeg WebAssembly runs entirely inside your browser tab. M4A files are decoded and FLAC files are generated locally — nothing leaves your device.
//related_converters
Related Converters
Similar conversions you might need.
Convert AAC to FLAC
Convert AAC audio to FLAC lossless format for archival.
→Convert M4A to MP3
Convert Apple M4A audio files to universally compatible MP3.
→Convert AAC to WAV
Convert AAC audio to uncompressed WAV for editing in DAWs and audio tools.
→Convert AAC to OGG
Convert AAC audio to OGG Vorbis for open-source ecosystems and Linux compatibility.
→Convert M4A to WAV
Convert M4A (AAC) audio to uncompressed WAV for editing in DAWs, broadcast, and forensic workflows.
→Convert M4A to OGG
Convert M4A (AAC) to OGG Vorbis for open-source media libraries, game engines, and Linux ecosystems.
→