M4R to AAC Converter

What happens when you convert M4R to AAC

• The audio is decoded and written as AAC at 192 kbps in an ADTS stream.
• Going from one lossy format to another adds a small generation loss. Choose a bitrate at least as high as the source to keep it inaudible.

How to convert M4R to AAC online

1. Press "Choose M4R files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
2. Adjust the settings if you need to: the bitrate controls quality and size. The defaults suit most people.
3. Press "Convert to AAC". The first audio or video conversion downloads the converter engine, about 32 MB, which your browser then keeps for next time.
4. Save each AAC with its download button. Close the tab and every trace of the files is gone from memory.

Why convert M4R to AAC?

M4R files usually come from custom ringtones and alert tones on iPhone. People convert them to AAC because raw AAC streams are what some broadcasters, podcast tools and hardware players ask for.

In short, M4R is good at what it was made for, and AAC is the more practical choice when the file has to play on another device or app. M4R plays in browsers that play M4A; iPhones use it as a ringtone, while AAC plays in all current browsers and on Apple and Android devices.

How to convert M4R to AAC on Windows, Mac, iPhone and Android

On Windows

Open this page in Chrome, Edge or Firefox, drag your M4R files in from File Explorer, and press Convert. Each AAC is saved to your Downloads folder. If you prefer a desktop program, VLC can also convert M4R to AAC: choose Media, then Convert / Save.

On a Mac

Safari, Chrome and Firefox all work. Drag the M4R files from Finder onto the drop zone and the AAC files land in Downloads.

On iPhone and iPad

Open the page in Safari and tap Choose M4R files. You can pick from Photos or from the Files app. The converted AAC appears in Files, in the Downloads folder.

On Android

Open the page in Chrome, tap Choose M4R files and pick them from Files or your gallery. The AAC is saved to the Download folder, where any file manager can find it. Keep the screen on while a long video converts, because Android may pause a tab in the background.

Best settings for M4R to AAC

AAC is a lossy format, so the bitrate decides both the sound quality and the file size. Size grows in a straight line with bitrate: double the bitrate and the file doubles.

The M4R was already compressed, so pick a bitrate at least as high as the original. Going higher does not add quality back, it only makes the file bigger.

M4R vs AAC: the differences

About M4R and AAC files

What is an M4R file?

M4R is an M4A file with a different extension that tells iPhone and Finder to treat it as a ringtone. Ringtones are limited to 40 seconds.

What is an AAC file?

AAC was designed as the successor to MP3 and sounds better at the same bitrate, especially below 128 kbps. A bare .aac file is a raw stream with no chapters or cover art; the same audio in a container is usually called M4A.

M4R to AAC not working? Common problems

• The conversion is slow. Audio and container changes take seconds, but re-encoding video runs on your own processor. Lower the resolution to 720p, close other tabs, and keep the device plugged in.
• The tab stops or reloads on a very large file. Browsers limit how much memory one tab can use, around 2 GB and less on phones. Split long recordings or convert them on a computer.
• Song titles are missing. Tags such as title and artist are copied when AAC can store them, but cover art is not carried over.

Convert M4R to AAC with ffmpeg

This converter runs ffmpeg inside your browser. If you would rather use the ffmpeg command line on your own computer, this command produces an equivalent AAC with the same kind of settings:

ffmpeg -i input.m4r -vn -c:a aac -b:a 192k -f adts output.aac

Replace input.m4r with the name of your file. For a whole folder of M4R files, run the command in a loop, or drop them all on the converter above, which processes them one after another.