What is AIFF? Apple Audio, PCM, Sample Rate, Bit Depth, and AIFF Converter Tools

What is an AIFF file?

AIFF stands for Audio Interchange File Format. It is an audio file format created by Apple for high-quality sampled sound. AIFF files usually use the extension .aiffor .aif.

In everyday use, AIFF usually means uncompressed PCM audio. That makes it similar to WAV: large files, simple decoding, and strong editing quality. AIFF is especially familiar in Apple-oriented production workflows, sample libraries, music editing, and audio interchange.

AIFF is not a compact delivery format. It is a working format. Use it when editability and quality matter more than file size, then export MP3, AAC, M4A, OGG, or Opus when you need a smaller listening copy.

A brief history of AIFF

AIFF was built on the Interchange File Format idea and became closely associated with Macintosh audio tools. Its purpose was straightforward: store high-quality sampled audio in a structured way.

How AIFF stores audio

A typical AIFF file stores audio as PCM samples. PCM is direct sample data: measurements of the audio waveform at a chosen sample rate and bit depth. This is why AIFF is easy for editors and digital audio workstations to process accurately.

Unlike MP3, AAC, OGG Vorbis, or Opus, ordinary AIFF does not use lossy perceptual compression. It does not try to guess what listeners will miss. It stores the waveform at the chosen resolution.

1. The analog sound is measured many times per second.
2. Each measurement becomes a digital sample.
3. The samples are stored with a selected bit depth.
4. The AIFF chunks describe how software should read the audio.

What is inside an AIFF file?

AIFF is chunk-based. A basic file includes a container chunk, a common chunk describing the audio, and a sound data chunk containing the samples.

+------------------------------+
| FORM AIFF chunk              |  file type and overall size
+------------------------------+
| COMM chunk                   |  channels, sample frames, bit depth, rate
+------------------------------+
| optional chunks              |  markers, names, comments, application data
+------------------------------+
| SSND chunk                   |  audio sample data
+------------------------------+

AIFF can also store markers, names, comments, loop information, and application-specific data. Support for those extras depends on the audio software reading the file.

PCM, sample rate, and bit depth

Three settings define most ordinary AIFF files: sample rate, bit depth, and channel count. Together they control the technical resolution and file size.

Sample rate

Sample rate is how many times per second the waveform is measured. Music commonly uses 44.1 kHz. Video workflows commonly use 48 kHz. Higher rates can be useful in production, but they create larger files.

Bit depth

Bit depth controls how many possible values each sample can store. A 16-bit AIFF is common for delivery-style PCM audio. A 24-bit AIFF gives more headroom for recording and editing.

Channels

Mono stores one channel. Stereo stores two. Multichannel AIFF can exist, but compatibility depends on the receiving software.

Why AIFF files are large

Uncompressed AIFF stores every sample. The file size is predictable:

bytes per second = sample rate * bit depth / 8 * channels

A three-minute stereo AIFF at 44.1 kHz and 16-bit is roughly 30 MB. The same audio as MP3, AAC, or Opus can be much smaller, which is why AIFF is better for production than everyday delivery.

Metadata, loops, and markers

AIFF can store metadata and production information, including names, comments, markers, and loop points. This can be useful for samples, sound libraries, and editing sessions.

• Use clear filenames because metadata display can vary between apps.
• Check whether markers and loops survive when moving between editors.
• Remove private comments or application data before publishing.
• Export compressed delivery copies for listeners who do not need source-quality audio.

AIFF vs WAV, MP3, FLAC, AAC, OGG, Opus, and M4A

AIFF is closest to WAV: both are usually uncompressed PCM working formats. WAV is more universal across platforms, while AIFF remains familiar in Apple and music-production workflows.

A practical workflow is to keep AIFF, WAV, or FLAC as the source-quality copy, then export MP3, AAC, M4A, OGG, or Opus when you need a smaller file.

AIFF on the web

AIFF is not a common web delivery format. Files are large, browser support is less predictable than MP3 or AAC, and many visitors do not need uncompressed audio. Use AIFF for downloads meant for editing, not ordinary playback.

<audio controls preload="metadata">
  <source src="/audio/sample.aiff" type="audio/aiff" />
  <a href="/audio/sample.aiff">Download the AIFF</a>
</audio>

For public listening, provide MP3, AAC/M4A, OGG, or Opus instead. If you offer AIFF, show the file size and make it clear that the file is intended for editing or production use.

When AIFF is the right choice

Choose AIFF when you need uncompressed audio and the receiving workflow is Apple-oriented or production focused.

• Use AIFF for editing, sampling, sound design, and production handoff.
• Use AIFF when a music or Apple-oriented workflow specifically requests it.
• Use WAV instead when cross-platform PCM compatibility matters more.
• Use FLAC instead when you want lossless storage in less space.
• Use MP3, AAC, M4A, OGG, or Opus when you need small files for sharing.

In short: AIFF is a high-quality working format. It is excellent before and during editing, but usually too large for everyday publishing.

Tips before converting AIFF files

Decide whether you need a working copy or a delivery copy. If the next step is editing, keep AIFF or convert to WAV. If the next step is sharing, streaming, or embedding, export a compressed copy.

Practical export choices

• Cross-platform editing: convert AIFF to WAV.
• General sharing: convert AIFF to MP3.
• Apple/mobile playback: convert AIFF to AAC or M4A.
• Open web audio: convert AIFF to OGG or Opus.
• Archiving: keep AIFF if storage is fine, or convert to FLAC if you want lossless compression.