What Is AIFF? Understanding Apple's Answer to WAV

What exactly is AIFF?

AIFF — Audio Interchange File Format — is an audio file format Apple defined in the late 1980s. Its purpose was simple: to store audio data without any loss, in a standard and portable structure. It still turns up today across the macOS ecosystem, in software like Logic and GarageBand, and in professional audio deliveries.

Technically, AIFF holds uncompressed PCM audio. PCM is the analog audio waveform measured at regular intervals and converted into numerical values. AIFF writes those measurements to the file exactly as they are — nothing is discarded, nothing is guessed, nothing is recalculated.

The consequence of this approach is clear: perfect quality, enormous files. At a 44.1 kHz sample rate, 16-bit depth, in stereo, a recording occupies roughly 10 MB per minute.

Its relationship with WAV: two implementations of the same idea

The easiest way to understand AIFF is to think about it alongside WAV. Both were born in the same era, in response to the same need, and both do the same fundamental job: putting raw PCM audio into a container.

The differences between them stay in the technical details:

• Origin: AIFF was defined on the Apple side, WAV by Microsoft and IBM.
• Byte ordering: The two store the bytes of the data in different orders. This is a detail software accounts for when reading the file, and it doesn't concern you as a user.
• Metadata: AIFF's metadata structure is in some cases more flexible than WAV's, though neither format reaches the tag richness of modern formats like FLAC.

In terms of audio quality there is no practical difference between them. An AIFF and a WAV recorded with the same settings carry the same audio information. Converting one to the other therefore doesn't change quality; it only changes the container. That clears up a common misconception: there's no such thing as "AIFF is better because it's the Apple format."

What does being uncompressed gain you, and what does it cost?

What it gains

There is no quality loss. The audio you recorded sits in the file exactly as it was. That's a critical advantage during production.

No generation loss occurs. When you open a file, edit it, and save it again, nothing degrades in AIFF. In lossy formats, every save cycle brings a fresh drop in quality. This is why staying in a lossless format during editing is a fundamental rule.

It's simple to read. Because the data isn't compressed, the software has no decoding work to do; it reads directly. In multi-channel projects and low-latency scenarios, this reduces processor load.

What it costs

Size. The biggest drawback. An album's worth of AIFF quickly reaches gigabytes; sending it by email, copying it to a phone, or uploading it to the web isn't practical.

Limited tag support. Information like artist, album, and cover art isn't carried as richly or as standardly in AIFF as it is in FLAC or MP3. For anyone trying to keep a large music library organized, this is a genuine point of friction.

Device compatibility. Professional software opens it without issue, but car stereos, older portable players, and many embedded systems don't recognize AIFF.

AIFF-C: don't judge by the extension

There's one detail worth knowing: AIFF has a variant called AIFF-C that supports compression. This variant can host different codecs and its file size may be noticeably smaller.

The practical implication is this: don't assume a file's contents are definitely uncompressed just because the extension says AIFF. If you're looking at an AIFF file that's much smaller than you expected, check its properties to confirm what it actually is. This is a good example of how a file format's name doesn't always fully describe its contents.

When should you use AIFF, and when should you convert?

Situations where staying in AIFF makes sense:

• You're still editing a recording — cuts, level adjustment, effects, and similar work should be done in a lossless format.
• You're working in a macOS-based production chain and your software handles AIFF smoothly.
• You're delivering a job and the recipient wants a lossless source.
• You're keeping the master copy in your long-term archive.

Situations where converting makes sense:

• You're going to share the file, upload it, or copy it to a phone. At that point, converting AIFF to MP3 is the practical solution.
• You'll listen on a device that doesn't recognize AIFF, such as a car stereo or portable player.
• Storage space is becoming a problem and you want to stay lossless — FLAC is a good middle path, storing the same audio data at roughly half the size with much better tag support.

There's one rule to remember when converting: moving from AIFF to MP3 is a moment of real loss. Because the source is lossless, this is the point at which the recording loses audio information for the first time, and there's no going back. That's why you shouldn't delete your original AIFF file; it's your master copy and it cannot be reproduced from an MP3.

In summary

AIFF is the Apple world's uncompressed audio format, and it does practically the same job as WAV: storing raw PCM audio losslessly. Its strengths are quality and suitability for editing; its weaknesses are size, tag support, and device compatibility. Staying in AIFF is the right choice during production and archiving; once you reach the point of sharing the file or listening on a portable device, converting to a distribution format like MP3 is what's needed. As long as you keep your master copy, you can redo that conversion whenever you like, with whatever settings you like.