AAC to FLAC Converter

Convert AAC files (and the AAC inside M4A containers) to FLAC — useful for editing workflows, library normalisation, and getting Apple ecosystem audio into a format every audio tool reads.

AACFLAC

Drop your AAC file here or click to browse

AAC (.aac) · Max 20 MB

Free — 10-second preview, 5 conversions/month. Upgrade for unlimited

What is AAC?

Advanced Audio Coding. Successor to MP3 with improved compression. Widely used in streaming services.

What is FLAC?

Lossless compression. Perfect quality at roughly half the size of WAV. The choice for audiophiles and archiving.

Why Convert AAC to FLAC?

AAC is excellent for distribution: smaller than MP3, near-transparent at 192–256 kbps, supported on every Apple device. But it has rough edges in production workflows. Many DAWs (Pro Tools especially) handle AAC unevenly — sometimes it imports as a different sample rate, sometimes it complains about the container. Audio restoration tools, podcast editors, and broadcast deliverable workflows all prefer FLAC or WAV. Converting AAC → FLAC gives you a stable, lossless container that every editor reads natively. Note: AAC is lossy. Converting to FLAC does not restore quality — the FLAC stores whatever the AAC decoded to, losslessly, with no further degradation. The benefit is workflow stability and library consistency, not better audio. The conversion handles both '.aac' (raw ADTS streams) and '.m4a' (AAC inside MP4 container) — the same tool, since the audio is identical, only the wrapper differs. If your M4A actually contains ALAC (Apple Lossless) instead of AAC, the conversion is bit-perfect (lossless to lossless).

Who Uses This Converter

DAW import for editing

Audio editors and DAWs handle FLAC more reliably than AAC. Convert before importing to avoid sample-rate quirks and unsupported-format errors.

Library normalisation

Standardise a mixed AAC/MP3/FLAC library to one lossless container. Your archive becomes consistent and editor-friendly.

Audio restoration projects

Restoration tools (iZotope RX, Adobe Audition's restore tools) work best on lossless input. Convert AAC sources to FLAC before any restoration work.

Frequently Asked Questions

Will the FLAC sound better than the AAC?

No. AAC is lossy; the audio inside is whatever the encoder produced. FLAC's lossless compression is applied to the decoded AAC waveform — the audible quality is identical to the source. You gain compatibility, not quality.

What about M4A files that contain ALAC, not AAC?

If your M4A holds ALAC (Apple Lossless), the conversion to FLAC is bit-perfect — both formats are lossless, so the FLAC is a sample-accurate copy. Check in iTunes (File → Get Info → File tab) to see whether your M4A is AAC or ALAC.

How much larger will the FLAC be?

Typically 4–7× the AAC size for music. A 5 MB AAC at 192 kbps becomes a 20–35 MB FLAC. Hi-quality AAC (256 kbps+) compresses closer to 3–4× when re-wrapped as FLAC. ALAC source files produce FLACs of similar size.

Does this work on Apple Music files?

Only on un-DRM-protected files. Apple Music streaming downloads are DRM-locked and cannot be converted. Files purchased from the iTunes Store after 2009 are DRM-free AAC and convert fine. Personal AAC rips and YouTube AAC extractions also convert without issue.

Will tags transfer to FLAC?

Common tags (title, artist, album, year, track number, genre) transfer from M4A's iTunes-style atoms to FLAC's Vorbis comments. Album art transfers. Composer, BPM, and other less-standard tags may need re-tagging in MusicBrainz Picard or Mp3tag.

Should I convert to WAV instead?

FLAC is roughly half the size of WAV at the same quality, has better metadata support, and is the standard for music libraries. Pick WAV only if a specific tool requires it (some hardware samplers, broadcast workflows) or you need raw PCM compatibility.