Convert AAC to FLAC Online
Need to convert AAC to FLAC right now? Drop your file and get results in seconds. Everything runs in your browser. Your audio never leaves your device.
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AAC (.aac) · Max 20 MB
AudioUtils converts AAC to FLAC using WebAssembly. The entire process happens locally. No upload, no server, no waiting in a queue.
Open any browser. Pick your file. Click convert. The FLAC file downloads instantly. Works on any device with a modern browser.
AAC is lossy. Converting to FLAC won't restore lost data, but gives you an uncompressed container for editing workflows. Free tier handles input files up to 20MB file size limit with a 10-second preview output. Upgrade to Pro for unlimited, full-length conversions up to 500MB file size limit.
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.
About AAC
Advanced Audio Coding. Successor to MP3 with improved compression. Widely used in streaming services.
About FLAC
Lossless compression. Perfect quality at roughly half the size of WAV. The choice for audiophiles and archiving.