M4A to AIFF Converter

M4A to AIFF — Why Convert, and What Actually Changes

What this conversion does depends entirely on what's inside your M4A. Most M4A files hold lossy AAC audio, and unpacking that to uncompressed AIFF does not restore any lost detail — the AAC encoder already discarded it, so the AIFF is just a much larger copy of the same lossy sound. If your M4A holds ALAC (Apple Lossless), this is a true bit-perfect unpack to PCM. Either way the real reason to convert is workflow: AIFF is the uncompressed PCM format that Logic Pro, GarageBand, older DAWs, and hardware samplers import natively.

M4A vs AIFF — Side-by-side

When to Convert M4A to AIFF

• You're importing into Logic Pro, GarageBand, or another DAW that prefers uncompressed PCM and would otherwise transcode the M4A anyway.
• You're feeding a hardware sampler or older audio tool that accepts AIFF/WAV but not AAC-in-M4A.
• You want to edit once in uncompressed PCM so repeated edits and saves don't trigger repeated lossy re-encodes of an AAC source — decode to AIFF first, then edit.
• Your M4A is ALAC (Apple Lossless) and you want a maximum-compatibility uncompressed master with no decode step at playback.

When to Stay on M4A (or Pick Something Else)

• You only care about storage, transfer, or listening — converting a lossy AAC M4A to AIFF inflates the file with zero quality benefit.
• Your M4A is AAC and you just want a different small format — convert M4A to MP3 instead of bloating it to uncompressed AIFF.
• You want AIFF's audio in the cross-platform container — output WAV via M4A to WAV; it's the little-endian equivalent and sounds identical.
• You need rich tagging preserved — AIFF's metadata support is thinner than M4A's, so some fields may not survive.

How to Convert M4A to AIFF

1. Upload Your M4A File: Drag and drop your .m4a files onto the page or click "+ Add Files". You can queue several and convert them with the same settings.
2. Set Audio Channel and Sample Rate: Leave Audio Channel and Audio Sample Rate on "Original" for a 1:1 copy of the source, or change them only if a target device needs mono or a specific rate.
3. Trim (Optional): Use the Trim control to keep just a section of the track; leave it "Unchanged" to convert the whole file.
4. Convert and Download: Click "Convert" and download your AIFF. No sign-up, no watermark.

Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — never shared or made public.

Frequently Asked Questions

Will converting M4A to AIFF improve the audio quality?

Only if your M4A is ALAC (Apple Lossless), in which case AIFF holds the same bit-perfect PCM. If your M4A is the far more common lossy AAC, the answer is no: the AAC encoder permanently discarded detail to shrink the file, and decoding to AIFF cannot bring it back. The AIFF will sound identical to the AAC — just much larger. Anyone promising a fidelity boost from a lossy source is mistaken.

How can I tell whether my M4A is AAC or ALAC?

M4A is a container, so the extension alone doesn't tell you. Files from the iTunes Store, Apple Music downloads, voice memos, and most exports are AAC (lossy). Files explicitly ripped or exported as "Apple Lossless" are ALAC. If you ripped a CD in the Music/iTunes app and chose the Apple Lossless encoder, it's ALAC; if you left the default AAC encoder, it's lossy. When in doubt, assume AAC — that's the safer assumption for quality expectations.

Why is my AIFF file so much bigger than the M4A?

Because AIFF stores every sample uncompressed while M4A compresses. CD-quality AIFF (16-bit, 44.1 kHz, stereo) runs around 10 MB per minute, so a 4-minute track lands near 40 MB regardless of how small the source M4A was. A 128 kbps AAC M4A of that same track might be only 4 MB, so expect a roughly tenfold jump. The extra bytes are uncompressed padding, not added detail.

Should I convert to AIFF or ALAC for Apple workflows?

It depends on the step. For importing into Logic Pro or GarageBand, uncompressed AIFF is a clean, decode-free choice. For storage or library files on Apple devices, ALAC is also lossless but stays roughly 40–60% of an AIFF's size because it's compressed. Use AIFF when you want an uncompressed working file; use ALAC when you want Apple-native lossless without the size penalty.

What's the difference between AIFF and WAV for this conversion?

They're close cousins: both are uncompressed PCM containers and sound identical. AIFF is big-endian and based on Electronic Arts' IFF format; WAV is little-endian and based on RIFF. AIFF is the more natural fit on macOS and in Apple's apps, while WAV is the cross-platform default. If you'd rather output WAV, use M4A to WAV.

Why decode to AIFF before editing instead of editing the M4A directly?

Because every time you re-save a lossy AAC file after editing, the encoder runs again and throws away a little more detail — generational loss stacks up over multiple passes. Decoding once to uncompressed AIFF gives you a stable PCM working file you can cut, fade, and process repeatedly without any further lossy re-encoding. Export back to a compressed format only at the very end, once.

What bit depth and sample rate will the AIFF have?

In our testing, leaving Audio Channel and Audio Sample Rate on "Original" produces an AIFF that matches the decoded source — commonly 16-bit PCM at 44.1 kHz for a typical AAC M4A, or whatever depth and rate an ALAC source carried. The converter does not upsample, so a 44.1 kHz source yields a 44.1 kHz AIFF, not a higher-resolution one. To go the other direction later, our AIFF to M4A tool re-packs it.