What MP3 bitrate is best for AIFF to MP3 conversion?

256 kbps is the sweet spot for music. It is indistinguishable from the AIFF source for almost all listeners in blind tests, and produces a file roughly 8% the size of the AIFF. Use 320 kbps if the recipient may re-encode the file again or if the music has heavy high-frequency content. Use 192 kbps if file size is the priority and the audience is listening on phones and laptops. 128 kbps is acceptable only for voice content. There is no benefit above 320 kbps — that is the MP3 spec ceiling.

Does converting AIFF to MP3 lose audio quality?

Yes, but the loss is inaudible at 256 kbps and above for most listeners on most equipment. AIFF is lossless PCM, so the MP3 encode is the only point at which information is discarded. The MP3 encoder uses a psychoacoustic model to remove audio it predicts the ear cannot detect. At 320 kbps the model has enough headroom that the result is transparent in blind testing. Always keep the AIFF master — once you delete it, the original quality is gone forever.

Can GarageBand export MP3 directly without an AIFF intermediate?

macOS GarageBand exports MP3 directly via Share → Export Song to Disk → MP3. iOS and iPadOS GarageBand does not — those versions only offer compressed AAC (M4A) or uncompressed AIFF/WAV. The recommended workflow even on macOS is to bounce to AIFF first, archive that, and convert to MP3 separately. This way you keep a lossless master for future remastering and you get full control over MP3 bitrate and encoding mode (CBR vs VBR), which GarageBand's built-in encoder hides behind generic 'quality' presets.

Why are AIFF files so large compared to MP3?

AIFF stores every audio sample uncompressed. A 16-bit 44.1 kHz stereo AIFF uses 10.6 MB per minute. A 24-bit 48 kHz file uses 17 MB per minute. MP3 uses a lossy psychoacoustic codec that discards audio the model predicts you cannot hear, typically reducing the file to 8-12% of the AIFF size. A four-minute 16-bit 44.1 kHz AIFF is about 42 MB; the same audio at 256 kbps MP3 is about 7.3 MB. The price for that compression is a small, usually inaudible loss of fidelity.

Is AIFF the same as WAV?

Functionally yes. Both are containers around Linear PCM audio. The differences are purely structural: WAV uses Microsoft's RIFF chunk format with little-endian byte order, AIFF uses Apple's IFF chunk format with big-endian byte order. Modern audio tools handle both transparently. Converting AIFF to WAV is lossless and instantaneous because the underlying samples do not change. The choice between the two today is mostly historical — Mac apps default to AIFF, Windows apps default to WAV, and any DAW reads either.

Will the AIFF to MP3 converter upload my file to a server?

No. The [AIFF to MP3 converter](/aiff-to-mp3) runs entirely in your browser using WebAssembly FFmpeg. The audio file is read by JavaScript on your machine, encoded by FFmpeg compiled to WebAssembly, and the resulting MP3 is offered as a download. The data never touches our servers. This matters for unreleased music, demo recordings, and any other audio you do not want exposed to a third party. The trade-off is that conversion speed depends on your CPU rather than a fast server, which is rarely a problem on modern laptops.

Should I keep the AIFF after converting to MP3?

Yes. The AIFF is your lossless master and the MP3 is a one-way derivative. You cannot recover AIFF quality from an MP3 — the data the encoder discarded is gone. Any future remastering, re-encoding to a different format, or delivering the track to a service that wants high-quality source has to start from the AIFF. If disk space is the concern, convert the AIFF to FLAC instead of deleting it: FLAC is bit-identical lossless and roughly half the size.

AIFF to MP3: GarageBand Exports and Quality Settings

If you have ever exported a track from GarageBand, bounced a mix in Logic Pro, or pulled audio off an older Mac project, you have probably ended up with a .aiff file that is too large to email, too large to upload, and unplayable on most non-Apple software. This guide walks through what AIFF actually is, why it produces files of that size, how to convert it to MP3 cleanly, and the bitrate that is right for whatever you intend to do with the result.

The fastest path is the AIFF to MP3 converter — it runs entirely in the browser, no upload, no install. Below is the context that makes the right settings choice obvious.

What AIFF Is and Why You Have It

AIFF stands for Audio Interchange File Format. Apple introduced it in 1988, based on Electronic Arts' IFF chunk format from the Amiga, and it has been the native uncompressed audio container on the Mac ever since. Inside an AIFF file is plain Linear PCM — the same raw digital audio that lives inside a WAV file. The two formats are functionally interchangeable; only the container header and byte order differ. See what is AIFF and what is WAV for the full background.

You typically end up with AIFF for one of these reasons:

GarageBand or Logic Pro export. Apple's DAWs default to AIFF when bouncing a mix.
iTunes or Music CD rip with the AIFF Encoder selected. Older Music app installs and the legacy iTunes still offer this.
Final Cut Pro audio export. Older Final Cut versions wrote AIFF; newer ones default to WAV but AIFF remains an option.
Field recordings on certain pro recorders (Sound Devices, Tascam DR-series in AIFF mode).
Stock loops and sample libraries distributed for Apple Loops or older Akai/E-mu samplers.

In every case the file is uncompressed PCM. That is what makes it big.

Why AIFF Files Are So Large

AIFF stores every sample literally. The math is unforgiving:

bytes per second = sample rate × (bit depth ÷ 8) × channels

A standard 16-bit, 44.1 kHz stereo AIFF runs 176,400 bytes per second — about 10.6 MB per minute. A three-minute song is roughly 32 MB. A 24-bit 48 kHz stereo bounce — Logic's typical default — is closer to 17 MB per minute. A 24-bit 96 kHz mix file weighs in at 35 MB per minute, so a five-minute high-resolution bounce easily exceeds 175 MB.

That is fine for an archive copy on a hard drive. It is not fine for emailing to a collaborator, uploading to SoundCloud, or sending through iMessage. MP3 typically reduces those files to 8–12% of the original size.

Why MP3 (and Why Not Always)

MP3 is the only audio format with truly universal compatibility. iPhone, Android, every car stereo, every podcast platform, every distributor, every browser. If you are sharing audio with someone whose playback environment you cannot predict, MP3 is the safe choice.

A few situations where MP3 is not the right target:

Apple-only sharing where size still matters: AIFF to M4A (AAC inside MP4) is more efficient than MP3 at the same bitrate and supported natively by every Apple device. See M4A vs MP3.
Editing in another DAW: convert AIFF to WAV instead — AIFF to WAV is lossless and faster than MP3 export.
Lossless distribution to audiophiles: convert AIFF to FLAC for half the file size with bit-identical audio.

For everything else — sharing, uploading, posting, distributing, listening on the move — MP3 is correct.

Converting AIFF to MP3 in the Browser

The AIFF to MP3 converter uses WebAssembly FFmpeg in a browser tab. The audio never leaves your machine — useful for unreleased material you do not want exposed to a server.

1. Open /aiff-to-mp3. 2. Drag your AIFF file into the drop zone or click to browse. Files up to about 500 MB convert without issue; larger files depend on browser memory. 3. Choose a bitrate (see the next section). 4. Click Convert. A four-minute song typically processes in 5–15 seconds on a modern laptop. 5. Download the MP3.

Multiple files can be queued in the same browser tab. The original AIFF is never modified.

Choosing the Right MP3 Bitrate

AIFF is lossless, so the MP3 encode is the only place quality is lost. The bitrate you choose should match how the file will be used and listened to:

128 kbps — Voice content, podcast rough cuts, demos sent for feedback. Music sounds visibly thinned at this bitrate, particularly cymbals, hi-hats, breathy vocals and acoustic guitar. Use only when file size is the dominant concern.
192 kbps — The transparency threshold for most listeners on most equipment. Good default for music shared casually with friends or posted on social platforms that re-encode anyway. A four-minute track at 192 kbps is roughly 5.7 MB.
256 kbps — Recommended for music you care about. Indistinguishable from the AIFF source for the overwhelming majority of listeners in blind tests. The sweet spot for personal music libraries and for sharing with other producers.
320 kbps — Maximum MP3 bitrate. Use when the recipient may re-encode the file again (you avoid compounding loss), when the music has a lot of high-frequency content (cymbals, strings, complex orchestral arrangements), or when you simply want zero compromise within the MP3 format.

Pick VBR V0 or V2 if the converter offers it. VBR allocates bits dynamically — more for complex passages, fewer for simple ones — and produces a smaller file at the same perceived quality compared with CBR. V0 averages roughly 245 kbps and V2 averages roughly 190 kbps. Read more in VBR vs CBR for MP3.

There is no benefit to encoding above 320 kbps because the MP3 specification caps there.

GarageBand-Specific Workflow

If you are exporting from GarageBand and your final destination is MP3, you can skip AIFF entirely:

macOS GarageBand: Share → Export Song to Disk → choose MP3 → pick a quality. "Higher Quality" is roughly 192 kbps; "Highest Quality" is 256 kbps CBR.
iOS / iPadOS GarageBand: Share → Song → choose Audio File → Compressed (Medium or High Quality) writes M4A; Compressed (Low Quality) writes a low-bitrate AAC. iOS GarageBand does not export MP3 directly — bounce to AIFF and use /aiff-to-mp3 on the AIFF.

Why bounce to AIFF first if you want MP3 anyway? Two reasons. One, you keep a lossless master for future re-mastering, format changes or distribution. Two, GarageBand's built-in MP3 encoder is fine but offers limited control over encoding mode and bitrate. Bouncing to AIFF and converting separately gives you full control of the MP3 settings.

Logic Pro Workflow

Logic offers more granular MP3 export through Bounce → File:

Stereo File / Surround File — your master bounce. Set to AIFF, 24-bit, project sample rate. Save this as the archive copy.
MP3 — enable the additional MP3 output. Logic uses the LAME encoder. Pick CBR 256 kbps for delivery to clients or 320 kbps for distribution masters.

Logic's MP3 encoding step is identical in quality to converting the AIFF afterwards with ffmpeg or our browser tool. The reason to do it separately is workflow flexibility — re-encoding from a saved AIFF lets you produce a 128 kbps preview, a 192 kbps social media cut, and a 320 kbps distribution copy without re-bouncing the mix from Logic.

Command Line: ffmpeg for AIFF to MP3

Useful for batch jobs and automation. Install ffmpeg ('brew install ffmpeg' on Mac) and:

Single file at VBR V2 (~190 kbps):

'ffmpeg -i input.aiff -q:a 2 output.mp3'

Single file at 320 kbps CBR:

'ffmpeg -i input.aiff -b:a 320k output.mp3'

Convert every AIFF in a folder, preserving metadata:

'for f in *.aiff; do ffmpeg -i "$f" -q:a 2 -map_metadata 0 "${f%.aiff}.mp3"; done'

The '-map_metadata 0' flag carries title, artist, album, year and other tags from the AIFF into ID3v2 tags on the MP3. Without it the MP3 will be untagged.

For more on bulk workflows, see how to batch convert audio.

AIFF vs WAV: A Quick Reality Check

AIFF and WAV both store Linear PCM. The audio data inside each is identical at the same sample rate and bit depth. The differences are purely structural: WAV uses RIFF chunks and little-endian byte order; AIFF uses IFF chunks and big-endian byte order. Original WAV had weak metadata support and AIFF had richer tag chunks, but modern tools normalize this — both formats round-trip through any DAW or converter without quality change.

If you are converting AIFF to MP3 for sharing, the format does not matter. If you are converting AIFF to WAV for use in a non-Apple DAW, that conversion is also lossless and instantaneous because no audio data is being changed.

See WAV vs AIFF for the long version.

Keep Your AIFF Master

Once you have an MP3, the AIFF should not be deleted. The MP3 is a one-way derivative — you cannot get the AIFF quality back from the MP3. Anything that requires re-mastering, alternate edits, format changes, or further processing has to come from the AIFF source. Treat the AIFF (or a FLAC compression of it) as your archive copy. The MP3 is your sharing copy.