ParrotNotes

M4A to MP3 Converter

A free M4A to MP3 converter for the file that will not open where you need it: a phone recording, a download, a track from your iTunes library. Many converter sites take your file onto their servers first. This page decodes it and writes the MP3 on your own device, so nothing is uploaded and no account is needed.

Drop your M4A here or click to browse

M4A, plus AAC, MP4 audio, WAV, OGG, WEBM, FLAC, OPUS and MP3, up to 100 MB and 30 minutes.

Your file stays on this device: the browser decodes it and the MP3 is written here, with no upload.

How to convert M4A to MP3

One file at a time, with nothing to install.

  1. 1

    Drop the M4A

    Drag the .m4a from your Downloads folder, the Files app or your music folder onto the converter, or tap to pick it. The page reads its length first and shows how big the MP3 will be.

  2. 2

    Set the bitrate

    128 kbps is preselected. If you know the bitrate of the M4A, match it or go above it; a higher number makes a bigger file, not a better recording.

  3. 3

    Convert and save

    Your browser decodes the audio and an MP3 encoder running inside the page writes the new file. Play the preview, then save it under the same name with .mp3 at the end.

Starting from the iPhone's Voice Memos app? The Voice Memo to MP3 Converter shows how to get the memo off the phone. Need an uncompressed file instead? Use the M4A to WAV Converter.

Where M4A files come from

M4A is the usual ending for an audio-only MPEG-4 file, so it turns up in more places than one.

  • Phone recordings

    Apple's guide says a rendered share from Voice Memos makes a single .m4a file, and some Android recorder apps save M4A as well. It is often what arrives when a recording leaves the phone.

  • Downloaded audio

    Course audio, interviews and recordings that people send you can all end in .m4a. The file is fine; the player, form or editor on the other side may not be.

  • iTunes and Music library files

    iTunes Plus purchases are .m4a files without copy protection. On a Mac, Apple's Music app can make its own copy: choose MP3 under Import Using in its import settings, then File > Convert. Apple says store purchases convert only if they are iTunes Plus songs.

  • Anything that wants MP3

    Some upload forms, older car stereos and audio tools list MP3 and leave M4A out. Wider support is the one real reason to convert, so if the M4A already plays where you need it, leave it alone.

What converting changes

M4A is the wrapper. The sound inside is usually AAC, sometimes Apple Lossless (ALAC). Turning either into MP3 means decoding it and compressing it again with a different codec.

From AAC, that is one lossy format after another: what was lost when the M4A was made does not come back, and a little more goes at this step. MDN describes AAC as designed for more compression with higher fidelity than MP3, so do not expect an MP3 at the same bitrate to beat the M4A. Keep the original if you have the room.

Size follows the bitrate you choose, not the file you started with. A 64 kbps M4A takes about 469 KB a minute; as a 128 kbps MP3 it takes about 938 KB, twice as much. If the MP3 has to be small, pick a lower bitrate here or use the Audio Compressor.

How big the MP3 gets

An MP3 is its bitrate times its length, whatever went in.

BitratePer minute10 minutes30 minutes
96 kbps703 KB6.9 MB20.6 MB
128 kbps938 KB9.2 MB27.5 MB
192 kbps1.4 MB13.7 MB41.2 MB
320 kbps2.3 MB22.9 MB68.7 MB
Kbps × 1,000 ÷ 8 × seconds; estimates. 1 MB = 1,048,576 bytes. The highlighted row is the default.

Which bitrate to pick

These are rules of thumb, not standards, and the choice stays yours in the converter.

  • Speech

    96 or 128 kbps. Meetings, lectures and phone recordings have little in them that a higher number would keep.

  • Music

    192 kbps is a sensible start. Go to 320 for a track you care about, knowing the file is two thirds bigger.

  • Files you will edit

    320 kbps, because each later export compresses the audio again. Better still, edit from the M4A you already have.

M4P, M4B and M4R files

These look like relatives of M4A, and this page turns all three away. An .m4p has its audio encrypted with Apple's FairPlay copy protection, and a converter cannot read it. An .m4b is the form audiobooks more commonly use, and an .m4r is what the iPhone uses for ringtones.

Which browsers convert M4A

The page uses your browser's own audio decoder, so the browser decides what opens. For AAC, MDN says Chrome supports it in MP4 containers, plain Chromium builds leave it out, and Firefox relies on what the operating system provides. If a file stops with a decode error, a second browser is the first thing to try.

Apple Lossless is narrower: MDN's codec table lists Safari as the only browser that supports ALAC. When decoding fails, the page reads the file's header and tells you if ALAC is the cause, so you know to reopen it in Safari on a Mac, iPhone or iPad.

The MP3 itself is written by an encoder inside the page, not by the browser. A mono recording stays mono and a stereo one stays stereo; a file with more channels keeps the first two.

Many M4A files start as voice recordings: how to transcribe a voice memo, Apple Voice Memos transcription, the Samsung voice recorder.

Recording it yourself? Go back to the words, not the file

The MP3 puts the audio in the right format. ParrotNotes records meetings, interviews and site visits on your phone and gives you the transcript and a summary, free for 100 minutes of recording a month.

Get Started Free

Related tools

M4A to MP3 FAQ

Sources