MP4 to AIFF Converter

Extract AIFF Audio From MP4: What This Tutorial Covers

This walk-through pulls the audio track out of an MP4 video and writes it as AIFF (.aif) — uncompressed linear PCM that Logic Pro, GarageBand, Pro Tools, and the macOS Music app read natively. There is no video in the output; you get the soundtrack as a standalone Apple-style audio file. It also explains why the AIFF comes out much larger than the MP4 and when extracting to AIFF is the wrong choice.

How to Convert MP4 to AIFF

1. Upload Your MP4 File: Drag and drop, or click "Add Files" to select an MP4 (.mp4 or .m4v) from your computer. Files upload over an encrypted connection; batch is supported, so you can queue several clips at once.
2. Pick Audio Codec, Sample Rate, and Channel: Open Advanced Options. Audio Codec defaults to PCM 16-bit Big Endian (standard AIFF); PCM 24-bit is also available for mastering work. Leave Audio Sample Rate and Audio Channel on Original to keep the MP4's embedded values, or set them explicitly (44100 Hz for CD-style delivery, 48000 Hz to match a video timeline; Mono to halve size on voice-only sources).
3. Trim (Optional): Switch Trim from Unchanged and enter a Start time and Duration to extract a single phrase, song section, or sound bite instead of the whole track.
4. Convert and Download: Click Convert and download the .aif. No sign-up, no watermark.

Walk-through: Choosing Codec, Sample Rate, and Channel

The defaults work for most people — the converter copies the MP4's sample rate and channel layout and writes standard 16-bit big-endian PCM, which is exactly what a DAW on macOS expects. Change the settings only when you have a reason:

• Want a CD-ready master: set Audio Sample Rate to 44100 Hz and keep PCM 16-bit Big Endian. That is the Red Book sample rate the Music app and disc-burning tools assume.
• Cutting audio back into a video edit: set 48000 Hz so the AIFF lines up with the 48 kHz audio standard most video timelines use; resampling 44.1↔48 later is avoidable work.
• Voice, interview, or lecture audio that was recorded mono: set Audio Channel to Mono. A mono AIFF is roughly half the size of stereo with no loss when the source already had one channel.
• Feeding a mastering chain that wants extra headroom: choose PCM 24-bit. The file is about 1.5x the size of 16-bit; only worthwhile if the source MP4 actually carried more than 16-bit audio, which is rare.

A practical size reference for uncompressed PCM: at 44.1 kHz 16-bit stereo the data rate is fixed at 1,411 kbps, which works out to about 10.1 MB per minute. Mono at the same rate is about 5.0 MB per minute, and 48 kHz stereo is about 11.0 MB per minute. These numbers do not depend on how loud or complex the audio is — PCM stores every sample at full width regardless.

Common Errors and How to Fix Them

• "The AIFF doesn't sound any better than the MP4." It won't. MP4 almost always stores audio as AAC, which is lossy. Converting to AIFF decodes that AAC and stores the result as uncompressed PCM — it preserves the quality that survived the original AAC encode but cannot rebuild detail that AAC already discarded. AIFF's win here is workflow (no re-decode in your DAW, no further generation loss), not a quality upgrade.
• "The output file is huge." That is expected: AAC in the MP4 might be ~1–2 MB per minute, while AIFF is ~10 MB per minute for 44.1 kHz 16-bit stereo. To shrink it, set Audio Channel to Mono when the source is mono, lower the Audio Sample Rate, or use Trim to keep only the section you need.
• "Windows won't open the .aif." Windows Media Player does natively support AIFF (.aif, .aifc, .aiff) via its PCM decoder, but the newer Media Player and Films & TV apps are inconsistent. If a file won't open, VLC, foobar2000, and Audacity all read AIFF reliably on Windows.
• "I need 24-bit but only got 16-bit." The default codec is PCM 16-bit Big Endian. Switch Audio Codec to PCM 24-bit before converting, or convert to WAV instead, which is the more common home for higher-bit-depth audio on Windows.

When This Doesn't Work

If the MP4 is DRM-protected (for example, a purchased title), the audio track cannot be extracted and the conversion will fail — that protection is the point of the DRM. A truncated or partially-downloaded MP4 can also error out because the audio track index is incomplete; re-download the file and try again. And if your goal is a small, shareable audio file rather than an uncompressed master, AIFF is the wrong target — use MP4 to MP3 for distribution or MP4 to FLAC for lossless audio at roughly half the AIFF size.

Frequently Asked Questions

Will extracting to AIFF give me better audio than the MP4 had?

No. AIFF is an uncompressed container, not a quality restorer. MP4 audio is normally AAC (lossy), so the AIFF holds the AAC-decoded samples as PCM — same audible quality, much larger file. AIFF only carries true lossless quality when the MP4's audio was already PCM, which is uncommon. What you reliably gain is a file your DAW reads without re-decoding AAC on every pass, and no extra generation loss as you edit.

Why is the .aif so much bigger than my MP4?

Because the MP4 stored audio compressed (AAC at roughly 1–2 MB per minute) and discarded the video you didn't keep, while AIFF stores audio uncompressed at about 10.1 MB per minute for 44.1 kHz 16-bit stereo. The audio alone expands several times over. Lower the Audio Sample Rate, switch to Mono if the source is mono, or Trim to the needed section to reduce the size.

Is .aif the same as .aiff? What about .aifc?

.aif and .aiff are the same format — Audio Interchange File Format, which Apple defined in 1988 on top of Electronic Arts' IFF container. The only difference is a 3- versus 4-character extension; both play identically. AIFC (.aifc) is Apple's compressed AIFF variant introduced in July 1991 that allows codecs like µ-law and A-law inside the AIFF wrapper; it is rarely used today. For the reverse direction, see AIFF to WAV.

What sample rate and bit depth does the output use by default?

By default the converter keeps the MP4's original sample rate and channel layout and writes PCM 16-bit big-endian, the standard AIFF encoding Logic, Pro Tools, and GarageBand assume. You can override Audio Sample Rate (8000–48000 Hz), Audio Channel (Mono/Stereo), and Audio Codec (PCM 16-bit or 24-bit) in Advanced Options before converting.

Can I pull out just one section instead of the whole track?

Yes. Set Trim to "Trim" and enter a Start time and Duration; only that segment is read from the MP4 and written to the AIFF, which trims both processing time and file size. For multi-region edits or fades, extract the full track first, then use Audio Cutter or Trim AIFF on the result.

Are my files kept after the conversion?

No. The MP4 is uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — no account, no watermark, and the audio track is not recompressed beyond the format change you requested. In our testing, a 3-minute 44.1 kHz stereo MP4 produced a roughly 30 MB AIFF (about 10 MB per minute), matching the uncompressed-PCM math above.