Will converting M4A to AIFF improve sound quality?

No. M4A uses AAC compression — a lossy codec that permanently discards audio data when the file was first encoded. Converting to AIFF does not restore that lost data. The AIFF file will sound identical to the source M4A. The benefit is that no additional quality loss occurs on re-encoding, and the file is stored in a widely compatible uncompressed container.

What is the best free tool to convert M4A to AIFF?

FFmpeg is the most reliable option: run `ffmpeg -i input.m4a output.aiff` from the command line. For a graphical interface, fre:ac (Free Audio Converter), Audacity, and dBpoweramp are popular choices on Windows and macOS. On macOS, iTunes/Music can also export imported tracks to AIFF.

How large will the AIFF file be compared to the M4A?

AIFF is uncompressed, so it is typically 5–10x larger than the equivalent M4A. A 5 MB M4A encoded at 128 kbps might yield a 25–50 MB AIFF file. The inspector on this page estimates the projected size based on your file's sample rate, channel count, and duration.

Is this inspector tool uploading my audio file anywhere?

No. All processing runs inside your browser using the Web Audio API. Your file is read into browser memory only and is never sent to any server. Refreshing the page clears all data.

What audio formats can the inspector read?

Any format your browser can decode natively: M4A, MP3, WAV, OGG Vorbis, AAC, FLAC (in supported browsers), and WebM. The inspector reads the decoded PCM properties — sample rate, duration, and channels — regardless of the source container.

What is the difference between M4A and AAC?

M4A is a file container (an MPEG-4 audio file) that typically holds AAC-encoded audio. AAC is the audio codec inside the container. When people say "convert M4A to AIFF," they mean: unwrap the AAC stream from the M4A container and re-package it as uncompressed PCM inside an AIFF container.

What is the difference between AIFF and WAV?

Both are uncompressed PCM containers of similar quality and file size. AIFF was developed by Apple and is the preferred format in macOS and Apple DAWs. WAV was developed by Microsoft and is more universal across Windows and Linux tools. For Apple-ecosystem work, AIFF is the natural choice; for cross-platform work, WAV is slightly more compatible.

Does AIFF support metadata tags?

Yes. AIFF supports ID3-style metadata including track title, artist, album, and artwork. FFmpeg preserves metadata from the source M4A when converting. Some older AIFF implementations have limited tag support, so verify tags in your target application after conversion.

M4A to AIFF Converter

Name: M4A to AIFF Converter
Availability: InStock
Author: Nham Vu

Inspect any audio file's metadata in your browser and learn exactly how to convert M4A to AIFF using free tools like FFmpeg.

Audio Metadata Inspector

Drop any audio file to see its properties and estimated AIFF size.

Drop audio file here or click to browse M4A, AAC, MP3, WAV, OGG, FLAC supported

Convert with FFmpeg

The fastest, free, cross-platform conversion command:

ffmpeg -i input.m4a output.aiff

Replace input.m4a with your file path. FFmpeg is free at ffmpeg.org.

GUI alternatives

fre:ac — free, open-source, Windows / macOS / Linux
Audacity — free multi-track editor with AIFF export
iTunes / Apple Music — macOS built-in AIFF export
dBpoweramp — paid, batch conversion, Windows / macOS

Drop an audio file on the left to inspect its metadata

No file is uploaded — everything runs in your browser

M4A vs. AIFF — What You Need to Know

M4A / AAC (Lossy)

Discards audio data permanently at encoding
Re-encoding degrades quality further
Small file size (3–10 MB typical)
Apple ecosystem default — iTunes, iOS, Apple Music

AIFF (Uncompressed)

Zero quality loss — bit-perfect playback
Preferred for Logic Pro, GarageBand, macOS DAWs
5–10x larger than equivalent M4A
Less universal outside Apple ecosystem

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Summary

Inspect any audio file's metadata in your browser and learn exactly how to convert M4A to AIFF using free tools like FFmpeg.

How it works

Drop any audio file (M4A, AAC, MP3, WAV, OGG) onto the inspector panel.
The Web Audio API decodes the file and reads its sample rate, duration, and channel count.
The inspector calculates the estimated uncompressed PCM size and projected AIFF file size at both 16-bit and 24-bit.
Use the recommended FFmpeg command or a desktop tool to perform the actual conversion.
Verify the output AIFF file in your DAW or media player before deleting the source.

Use cases

Prepare M4A voice memos or recordings for import into Logic Pro or GarageBand.
Archive an iTunes or Apple Music library in uncompressed AIFF for long-term preservation.
Check a file's sample rate and channel layout before conversion.
Estimate the disk space an AIFF archive will require.
Verify audio properties without installing a desktop audio editor.
Convert M4A podcast exports to AIFF for professional mastering sessions.
Teach yourself the difference between lossy AAC/M4A and uncompressed AIFF.
Confirm stereo vs. mono layout before sending tracks to a collaborator.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu