How to convert AIFF to MP3 on Mac (GarageBand, CD rips, batch)

You finished the song in GarageBand, bounced it, and got a 60 MB file ending in .aiff. Or you found a folder of CD rips from years ago, when someone set iTunes to import as AIFF “for quality”, and now there are 40 GB of them. Or a voice-over artist sent the takes as .aif files and the podcast host wants something smaller. The files sound perfect on your Mac. But the car stereo’s USB port ignores them, the Android phone won’t play them, the website’s audio player shows nothing, and the email bounces because the attachment is too large.

The fix is AIFF to MP3: the same audio at about a tenth of the size, playable on nearly every device and website. This guide covers how to convert AIFF to MP3 on a Mac, entirely on-device. You’ll find the Music app route that’s already installed, the free command-line route and the drag-a-folder route, plus two checks that can save you the conversion entirely.

In this guide11 sections

What AIFF is, and why it’s so big

AIFF (Audio Interchange File Format) is Apple’s uncompressed audio format, around since 1988. Inside is plain PCM audio, the raw samples with nothing squeezed out: the same audio WAV holds, in Apple’s wrapper. The .aif and .aiff extensions are the same format.

Uncompressed means heavy. At CD quality (16-bit, 44.1 kHz stereo) AIFF runs about 10 MB per minute, and 24-bit studio bounces weigh more. A four-minute song is around 40 MB, and a full album rip is 400 to 600 MB.

That’s why AIFF is everywhere on Macs that make music. GarageBand and Logic Pro bounce to it, older Apple Loops and many sample packs ship as .aif, and the Music app can import CDs with its AIFF Encoder. AIFF also carries proper tags (artist, album, artwork), which is why music people preferred it to WAV for CD rips. Outside Apple’s ecosystem, though, support thins out. Android doesn’t list AIFF among its supported formats, Chrome won’t play it in a web page, and most car stereos and portable players read MP3 and AAC but not AIFF.

Two checks before you convert anything

Do you still have the project? If the AIFF is a GarageBand or Logic bounce and the project still exists, export again as MP3 instead. In GarageBand that’s Share → Export Song to Disk, which offers MP3 alongside AAC, AIFF and WAV. Logic’s Bounce dialog has an MP3 option too. Encoding straight from the project skips one step, and you can still convert the AIFF later if you need to.

Is this AIFF a master? If it’s an original recording, a final mix or a lossless CD rip you can’t easily repeat, keep the AIFF archived and treat the MP3 as the copy that travels. MP3 discards audio data permanently, and converting an MP3 back to AIFF later gives you a big file of the same lossy sound. If the AIFF is disposable, like a one-off export or a file someone sent you, convert it and move on.

Does it have to be MP3?

MP3’s strength is universality: it plays in car stereos, cheap Bluetooth speakers, every browser, Android, Windows and old iPods. If any of those is the destination, MP3 is the answer. Two alternatives are worth a moment, though:

M4A (AAC) sounds slightly better than MP3 at the same bitrate and plays on every Apple device, Android phone and modern browser. If the destination is phones and websites rather than old hardware, it’s a fine choice.
ALAC (Apple Lossless) keeps every sample of the AIFF at roughly half the size. If the files are headed into your own Apple Music library, this is the lossless option. The same choice comes up in the FLAC guide.

Everything below works for any of the three. Only the output choice changes.

The built-in route: the Music app

The Mac’s only built-in MP3 encoder lives inside the Music app, and AIFF imports into Music without complaint:

Open Music → Settings → Files → Import Settings.
Set Import Using to MP3 Encoder and pick Higher Quality (192 kbps), or Custom for up to 320 kbps. Click OK.
Drag the AIFF files into the Music library.
Select the imported tracks and choose File → Convert → Create MP3 Version.
The MP3 copies appear in the library beside the AIFF versions. Right-click one and choose Show in Finder to get at the file.

It’s free, already installed, and tags such as artist and album come along. The catches show up past a few tracks. Everything has to go through your Music library, so you end up with both copies in it. The MP3s land wherever Music keeps its media, not in a folder you chose. And the MP3 setting stays on for every CD you import afterwards until you change it back.

Other built-in tools don’t help here. QuickTime Player’s Export As → Audio Only writes AAC in an .m4a file, not MP3. Finder’s Encode Selected Audio Files service also writes AAC or Apple Lossless. The Terminal tool afconvert can’t encode MP3 at all. It does make a good M4A, if you decided above that M4A will do:

afconvert -f m4af -d aac -b 256000 input.aiff output.m4a

For real MP3 files outside the Music app, you need one outside tool.

Skip the upload-a-file converter sites

A browser converter means uploading 40 MB per song, often against a free-tier size cap, then downloading the result. Your Mac can do the same job locally in a fraction of the time. For unreleased songs and client recordings there’s a second reason: once a file is uploaded, it’s on somebody else’s server. Both methods below run fully offline, with nothing leaving the Mac.

Method 1: ffmpeg (free, command line)

Install ffmpeg with Homebrew:

brew install ffmpeg

One file, maximum MP3 quality:

ffmpeg -i input.aiff -c:a libmp3lame -b:a 320k -id3v2_version 3 output.mp3

-c:a libmp3lame selects the LAME encoder and -b:a 320k sets MP3’s highest bitrate. ffmpeg copies the AIFF’s tags into the MP3, and -id3v2_version 3 writes them in the older ID3v2.3 form, which Windows and older players read most reliably. For smaller files that still sound transparent, replace -b:a 320k with -q:a 0 for variable bitrate around 245 kbps. For spoken word, -b:a 128k is plenty.

A whole folder, with both extensions covered:

cd ~/Music/aiff-rips
for f in *.aif *.aiff; do
  [ -e "$f" ] || continue
  ffmpeg -n -i "$f" -c:a libmp3lame -b:a 320k -id3v2_version 3 "${f%.*}.mp3"
done

-n tells ffmpeg not to overwrite anything already there, so you can run the loop again safely. Audio encodes quickly, so even a large rip collection finishes in minutes. For CD rips sorted into Artist/Album subfolders, the loop needs a find command instead, and from there you’re maintaining a script.

Method 2: Zumkor (drag the folder, done)

If your AIFF situation is a folder rather than a file, such as an old rip library, a season of podcast takes or a drive of session bounces, Zumkor turns it into one drag. It needs macOS 14 or later on an Apple silicon Mac:

Open Zumkor and drag in the AIFF files or the whole folder. You can also drop them on the Dock icon or right-click in Finder and choose Services → Add to Zumkor.
Pick MP3. M4A (AAC), ALAC, WAV, FLAC and Opus are there too, if you chose differently above.
Click Convert. Zumkor asks where to save, and the MP3s go to that folder while the AIFF originals stay where they are.

There’s no bitrate menu to puzzle over. Zumkor picks a high-quality bitrate on its own, around 256 kbps for MP3. Every row shows the exact filename it will produce before you convert, and the queue holds up to 2,000 files. Conversions keep running with the window closed, and the whole job happens on your Mac with nothing uploaded, Wi-Fi on or off.

Two details help with AIFF in particular. Bounces and voice takes often carry dead air at the start or a long tail of silence, and Zumkor can trim an audio file before converting: drag the yellow handles and only the kept range becomes the MP3. If AIFFs keep arriving, say a new bounce every week, the Convert Files action in Apple’s Shortcuts app lets you build the conversion into a shortcut, so the next batch is one click.

Pricing: everything is free for 7 days. After that you can keep converting 5 files a day (25 a week) for free, and audio is never watermarked (the small Zumkor mark goes on free videos only). A big rip library is a lot of days at that rate, which is what the Full Version is for: a one-time $19.99 purchase. Buy once and keep it forever. There’s no subscription and no account, and it’s shared with your family through Family Sharing.

The honest trade-off: for a handful of songs, the Music app is free and already installed, and ffmpeg is free if Terminal suits you. Zumkor earns its place with folders, with output that should land where you choose, and on a Mac that also collects WAV masters, M4A voice memos and FLAC downloads. One app converts all of it.

Getting the conversion right

256 to 320 kbps for music, less for voice. At those bitrates, nearly no one can tell an MP3 from the AIFF in a blind test. Speech is more forgiving: a 128 kbps MP3 of an interview sounds the same as the AIFF.
Keep masters, share copies. Archive original recordings and lossless rips on an external drive or cloud backup, and hand out the MP3s. Storage costs less than re-ripping a box of CDs.
Encode once. AIFF to MP3, then edit, then MP3 again stacks lossy encodes, and the artifacts add up. Edit the AIFF and encode once at the end. If a collaborator needs editable audio, send the AIFF or a lossless FLAC or ALAC.
Hi-res bounces convert fine. A 24-bit, 96 kHz AIFF becomes a normal 44.1 or 48 kHz MP3. For a copy that travels, that’s the point. The hi-res data stays in your archived original.
Check the tags after a batch. Open a few MP3s in the Music app or Finder’s Get Info and confirm artist, album and artwork came across before you delete any originals.

AIFF’s Windows twin is WAV: same audio, same size, same fix, and WAV to MP3 has its own guide. If what you really want is the soundtrack of a video, such as a filmed performance or a recorded talk, skip exporting it to AIFF first. Zumkor pulls the audio straight out of the video in one pass, as covered in MP4 to MP3.

The reverse trip exists too. Some samplers, DJ tools and editing workflows want uncompressed input, and Zumkor writes AIFF and WAV as readily as MP3. It won’t bring back quality the MP3 already discarded, though. It puts the same sound into a bigger container, as the MP3 to WAV guide explains.

Bottom line

A few songs, nothing to install: the Music app. Set Import Settings to MP3 Encoder, import the AIFFs, then File → Convert → Create MP3 Version.
Still have the GarageBand or Logic project: export or bounce straight to MP3 instead.
Comfortable in Terminal: ffmpeg -i input.aiff -c:a libmp3lame -b:a 320k -id3v2_version 3 output.mp3, looped for folders.
A whole folder or rip library: Zumkor. Drag the folder, pick MP3 and convert on your Mac into a folder you choose, up to 2,000 files per queue. Free for 7 days, then 5 files a day free, or a one-time $19.99 for everything.

Whichever route fits, keep the conversion on your Mac. Uploading gigabytes of your own recordings to a converter site to make them smaller is the one genuinely bad option.

FAQ

How do I convert AIFF to MP3 on a Mac without installing anything?

Use the Music app. Set Music → Settings → Files → Import Settings to MP3 Encoder, import the AIFF files, select them and choose File → Convert → Create MP3 Version. The MP3s land inside your Music library rather than a folder you pick, and remember to switch the import setting back afterwards.

Is AIFF better quality than MP3?

Yes. AIFF is uncompressed, so it holds every sample of the original recording, while MP3 discards data to make the file about a tenth of the size. At 256 to 320 kbps the difference is inaudible to nearly everyone. Keep AIFF for masters you’ll edit again and use MP3 for copies you share.

How do I batch convert a folder of AIFF files to MP3 on a Mac?

In Terminal, loop ffmpeg over the folder with a short for-loop. Or drag the whole folder into Zumkor, pick MP3 and click Convert. Zumkor converts up to 2,000 files per queue on your Mac with nothing uploaded, and the MP3s go to a folder you choose while the AIFF originals stay put.