AAC to MP3

About converting AAC to MP3

AAC is the sound format of phones, video and many music stores. It sounds good and it is small. You meet it in two kinds of files:

• .m4a — AAC inside an MP4 box. Phone voice memos, music downloads and many podcasts use it.
• .aac — "raw" AAC with no box around it (also called ADTS). Screen recorders, call recorders, dash cams, radio streams and some voice recorders save these.

A raw .aac file is the one that causes trouble. Many players, older car stereos, editors and websites refuse it — even some that play M4A. MP3 plays everywhere.

This tool turns any AAC file into an MP3, in your browser. Nothing is uploaded.

Features

• Raw .aac and .m4a — both kinds of AAC file, and AAC from MP4 video too
• MP3 out — or M4A, WAV, OGG or FLAC if you need them
• Pick the quality — 128 to 320 kbps; 192 kbps is set for you
• M4A tags are kept — the title, artist and album go into the MP3
• Listen first — play the result on the page before you save it
• Private — converted on your device, never uploaded

AAC or MP3 — what is the difference?

Both formats leave out sounds people hardly hear, to make the file small. AAC is newer and packs sound better: AAC at 128 kbps sounds about as good as MP3 at a higher bitrate. MP3 is older and plays on almost every device ever made.

So converting AAC to MP3 is not about better sound. It is about playing the file everywhere. Because it is a second round of packing, give the MP3 a bitrate one step higher than the AAC had:

Not sure what your file has? 192 kbps is a safe choice for most AAC files.

How big will the MP3 be?

An MP3's size is bitrate × length ÷ 8:

1 MB = 1,000,000 bytes. If your MP3 bitrate is higher than the AAC's, the MP3 will be bigger than the AAC file — that is normal.

What people use it for

• Playing a raw .aac recording from a screen recorder, call recorder or dash cam
• Making music play in an older car stereo or MP3 player
• Opening a sound in an editor or DJ program that only takes MP3
• Uploading audio to a site that only accepts MP3
• Turning the sound of a phone video (.mp4) into an MP3

Good to know

• Copy-protected music (old store files ending in .m4p) cannot be converted. That protection is there on purpose.
• A raw .aac file usually has no title or artist inside. Add them to the MP3 with the MP3 Tag Editor.
• For iPhone voice memos, the M4A to MP3 page explains how to get the file off the phone.
• The first conversion downloads the converter (about 30 MB) once. After that it starts at once.

Frequently asked questions

Is AAC better than MP3?

At the same bitrate, AAC usually sounds a little better. But MP3 plays on more devices — that is why people convert. If your device plays AAC, you can keep the AAC file.

Why does my .aac file not play?

A raw .aac file has no box around the sound. Many players expect a box (like .m4a) and give up. The MP3 from this page plays in all of them.

Will the MP3 sound worse?

If you pick a bitrate one step above the AAC's, almost nobody hears a difference. Converting can never make the sound better than the AAC was.

Is my file uploaded?

No. The conversion runs on your own device, inside this page. The file never reaches a server.

Related tools

• M4A to MP3 — for iPhone voice memos and music in .m4a
• Bulk Audio Converter — convert many AAC files at once
• MP4 to MP3 — take the sound out of a video
• Audio Converter — any audio format to MP3, WAV, M4A, OGG or FLAC
• MP3 Tag Editor — add the title and artist

How to use it

• Click Click to upload, or drag your .aac or .m4a file onto the box
• Leave MP3 selected as the format
• Pick the quality — 192 kbps fits most AAC files, 320 kbps for music downloads
• Press Convert to MP3 — the first run downloads the converter
• Play the result, then click Download MP3