AIFC to FLAC Converter

Convert AIFC to FLAC: What This Tutorial Covers

This walk-through is for anyone holding .aifc (AIFF-C) files — legacy Mac exports, GarageBand or Logic bounces, telephony captures — who wants them in FLAC, the open lossless format that plays in VLC, foobar2000, and most non-Apple players. The catch worth understanding up front: what FLAC can do for your file depends on what's inside the AIFC, so the first section explains how to tell, and the rest gets you a clean FLAC.

How to Convert AIFC to FLAC

1. Upload Your AIFC File: Drag and drop your .aifc file onto the page, or click "+ Add Files" to browse. Queue several at once and they convert in a single batch.
2. Set the Compression Level: Open Advanced Options and use the Compression level slider (1 to 12). A higher level produces a smaller FLAC and takes longer to encode; it never changes the audio, because FLAC decodes back to the exact samples it was given.
3. Adjust Audio Sample Rate or Channel (Optional): Leave Audio Sample Rate and Audio Channel on "Original" to preserve the source exactly, or change them if you specifically need to resample or downmix. Set Trim (default "Unchanged") to export only part of the track.
4. Convert and Download: Click "Convert" and download your FLAC file. No sign-up, no watermark.

Walk-through: PCM Inside vs a Lossy Codec Inside

AIFF stored only uncompressed PCM. In July 1991 Apple extended it as AIFF-C (written AIFC), adding a field in the file's COMM chunk that names a four-character codec — so an .aifc can hold very different things, and that decides what FLAC can do:

• If the AIFC holds uncompressed PCM (codec NONE, big-endian, or sowt, which is just little-endian PCM with no compression, or the float types fl32/fl64) — this is the common case, because macOS frequently writes plain audio into an AIFF-C wrapper. Here the conversion is truly lossless: FLAC keeps every sample bit-for-bit and usually shrinks the file to roughly half its size. macOS writing uncompressed audio as "AIFF-C/sowt" is exactly why a file that looks compressed often isn't.
• If the AIFC holds a lossy codec (ulaw, alaw, ima4 IMA ADPCM, or the old MAC3/MAC6 MACE codecs) — the audio was already degraded when the AIFC was made. FLAC will preserve exactly that already-lossy audio without adding more loss, but it cannot regain detail that the original codec threw away. You still get FLAC's open format and tagging; you do not get back CD quality that was never in the file.

Either way, picking FLAC is safe: it never makes the audio worse. If you are unsure which kind you have, just convert — the result is lossless relative to whatever the AIFC contained.

AIFC vs FLAC at a Glance

Common Errors and How to Fix Them

• "My FLAC isn't smaller than the AIFC" — Your AIFC almost certainly held a lossy codec (μ-law or IMA ADPCM), which is already small. FLAC can't compress already-compressed audio much further. That's expected, not a fault.
• "The FLAC won't play in iTunes or Apple Music" — Apple's apps don't support FLAC playback; their lossless format is ALAC. Play FLAC in VLC, foobar2000, or a DAP, or convert back with FLAC to AIFC for Apple-only workflows.
• "My file won't open here at all" — A few very old AIFCs use MACE 3:1/6:1, which most modern tools dropped years ago. The converter decodes these server-side, so a file that current QuickTime refuses to open will usually still convert.
• "I only need part of the track" — Set Trim before converting to export just a start-and-duration window rather than re-cutting the FLAC afterward.

When This Doesn't Work

A lossless container can't undo lossy history: if your AIFC was recorded as 8 kHz μ-law telephony, the output FLAC is still 8 kHz telephony audio — clean and compact, but not hi-fi. If you actually want a small, universally playable copy rather than a lossless one, a lossy target makes more sense — use AIFC to MP3 instead. And FLAC can't read a corrupted or DRM-wrapped source; the file has to be a real, playable AIFC to begin with.

Frequently Asked Questions

Will I lose any audio quality converting AIFC to FLAC?

FLAC itself never loses quality — it's lossless, so it stores the exact samples it's handed. What matters is what the AIFC already contained. If the AIFC is uncompressed PCM (the common NONE/sowt case macOS writes), the whole chain is lossless and the FLAC is bit-identical to the source. If the AIFC already used a lossy codec, FLAC faithfully preserves that lossy audio but can't restore what the codec discarded earlier. In neither case does converting to FLAC make things worse.

How can I tell whether my .aifc is actually compressed?

Check the codec named in the file's COMM chunk if your audio tool exposes it. NONE, sowt, fl32, and fl64 all mean uncompressed (PCM or float) — sowt is simply little-endian PCM, no compression at all, which is why macOS-written "AIFF-C" files are usually not compressed. Anything named ulaw, alaw, ima4, MAC3, or MAC6 is a lossy codec. If you can't check, a practical clue is size: a file under roughly 1 MB per minute of stereo audio is probably lossy already.

How much smaller will the FLAC be than the AIFC?

For uncompressed-PCM AIFCs, FLAC commonly lands around half the original size — denser music compresses less, quiet or sparse recordings more. In our testing, a 16-bit/44.1 kHz stereo source that was about 50 MB as uncompressed AIFC came down to roughly 28 MB as FLAC with no change to the audio. If your AIFC was already lossy, expect little or no size reduction, because there's not much left to compress.

Does the compression level change how the FLAC sounds?

No. The Compression level slider only trades encoding time against file size. Every level from 1 to 12 produces a perfectly lossless file that decodes to identical audio; a higher level just works harder to make the file a little smaller. There's no audio-quality setting to lose, because nothing is ever discarded.

Can I play FLAC on my Mac or in Apple Music?

Not in Apple's own apps. iTunes, the Music app, and iPods don't play FLAC — Apple's lossless format is ALAC. FLAC plays natively in VLC, foobar2000, and most modern non-Apple players and portable DAPs. If you live entirely inside the Apple ecosystem, you may prefer ALAC or keep the AIFF/AIFC source; you can also go the other way with FLAC to AIFC.

Will my tags and metadata carry over?

FLAC supports rich Vorbis-comment tags and embedded cover art, so it can hold more metadata than AIFC, whose NAME/AUTH/COMT tagging is limited and inconsistent between apps. Standard tags present in the AIFC are preserved where a direct FLAC equivalent exists; raw telephony or scientific captures often have empty metadata and produce untagged FLACs.

Are my uploaded files kept private?

Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public.