Free online AUP3 to MP3 converter

Music players, phones, car stereos, and sharing platforms generally cannot open an Audacity project directly, so an AUP3 file must be exported to MP3 for ordinary playback and distribution. The export creates a single compressed audio file from the project's current mix.

What the AUP3 format is

AUP3 is Audacity's project format, used by Audacity 3.0 and later. Unlike a finished audio file, it stores an editable project: tracks, clips, labels, effects, volume and pan settings, fades, project metadata, and the audio data required to reopen the work. The project is stored in a SQLite-based database.

An AUP3 file is intended to be opened in Audacity, not played by standard media players. Audacity 2.x and earlier cannot open it; use Audacity 3.0 or a later version. Keep the AUP3 file as the master if you may need to change edits, effects, track levels, or arrangement later.

What the MP3 format is

MP3 is a lossy, compressed audio format supported by most computers, phones, car stereos, media players, and publishing services. It produces much smaller files than uncompressed PCM audio or lossless formats, which makes it practical for playback, sharing, and portable storage.

MP3 encoding discards audio information that may be less audible. A higher bitrate generally retains more detail but produces a larger file; 192 kbps is a practical general-purpose setting, while 256–320 kbps is preferable when quality matters more than size.

How to convert AUP3 to MP3

Using Audacity

1. Install or open Audacity 3.0 or later and choose File → Open.
2. Select the .aup3 project and wait for Audacity to load its tracks and edits.
3. For a full-project export, leave the time selection unchanged. To export only part of the project, select the required time range; adjust track mute, solo, volume, pan, and effects before exporting.
4. Choose File → Export Audio. In the export dialog, choose MP3 Files as the format, then specify the destination and filename.
5. Choose the bitrate mode and quality. Use constant bitrate at 192 kbps for general use, or a higher bitrate for music where a larger file is acceptable.
6. Click Export, enter or edit the metadata if requested, and save the MP3.

If Audacity reports that an MP3 encoder is unavailable, use the current Audacity installation and follow its encoder setup prompt. Do not rename .aup3 to .mp3: an AUP3 database is not an MP3 stream, and general audio tools such as FFmpeg cannot normally decode the project directly.

Using 101convert.com

You can convert the file on 101convert.com for free without installing software: upload the AUP3 file, select MP3 as the output format, start the conversion, and download the result. Use Audacity instead when the recording is sensitive or when you need control over the selection, mix, effects, bitrate, and metadata.

Quality and compatibility limits

The MP3 contains the rendered audio from the export, not the editable Audacity project structure. Tracks, labels, clip boundaries, individual effects, and undo history cannot be edited independently in the MP3.

Audacity renders the project's current mute, solo, level, pan, effect, and sample-rate settings during export. Listen to the exported file before deleting the AUP3 project, particularly when the project contains multiple tracks or real-time effects.

MP3 export is lossy. Avoid repeated MP3 exports because each generation can reduce quality. Retain the AUP3 project and, for archival or further editing, export a lossless WAV or FLAC master as well.