Free online AUP3 to M4A converter

What the AUP3 format is

AUP3 is Audacity's project format, introduced in Audacity 3.0. It is an SQLite-based project database that stores track structure, labels, edits, envelopes, metadata, and audio data for a recording or multitrack session.

Audacity creates AUP3 files when you use File → Save Project → Save Project. The file is intended to be reopened in Audacity, not played directly by music apps. Renaming recording.aup3 to recording.m4a does not convert the audio because the file does not contain an M4A container or an AAC stream.

What the M4A format is

M4A is a filename extension commonly used for MPEG-4 audio files. The audio is often AAC, a lossy codec supported by phones, browsers, media players, podcast applications, and many video editors; some M4A files contain lossless ALAC instead.

AAC M4A files are substantially smaller than uncompressed WAV files at comparable listening quality. M4A is suitable for playback, distribution, and general editing, but it is not an ideal archival master because exporting to AAC discards audio information.

How to actually convert AUP3 to M4A

Using Audacity

1. Install and open Audacity, preferably the same or a newer version than the one that created the project.
2. Choose File → Open and select the .aup3 project.
3. Check the tracks, mute or solo channels as required, and set the selection or time range to export. Audacity exports the audible mix unless you specifically export selected tracks or channels.
4. Choose File → Export Audio, enter an output filename ending in .m4a, and select the M4A/AAC or FFmpeg M4A export option in the format list.
5. Set the AAC bitrate. 128–192 kb/s is typical for speech and general listening; 192–256 kb/s preserves more detail for music while producing a larger file.
6. Review the metadata fields, select Export, and play the resulting file in a compatible player.

Some Audacity installations do not include the FFmpeg component required for M4A/AAC export. If M4A is absent from the export format list, install the FFmpeg library supported by your Audacity version, restart Audacity, and repeat the export. Do not use File → Save Project; that saves another Audacity project rather than an audio file.

Using the built-in online converter

You can also upload the AUP3 file to 101convert.com, choose M4A as the output format, start the conversion, and download the result without installing software. Uploading a project sends its recording data to the service, so use Audacity for confidential material or projects containing sensitive recordings.

Quality, compatibility, and limitations

Exporting to AAC is lossy. If the project may need further editing, export a WAV master first through File → Export Audio, then create the M4A copy from the project or master. Converting an already lossy file to M4A cannot restore discarded detail.

The exported file contains the rendered mix, not Audacity's editable tracks, effects settings, labels, or undo history. Preserve the original .aup3 project when those elements may be needed later.

Sample rate and channel layout follow the export settings and project mix. Stereo music commonly uses 44.1 or 48 kHz; speech can use lower rates when file size matters. AAC M4A is widely supported, but software that accepts only MP3, WAV, or uncompressed audio may require another export format.