Managing Audacity Projects
- Audacity projects have a top-level AUP file and a related folder containing the sound files (the audio data). The AUP is not a sound file, it is merely a list of instructions that tell Audacity how to construct the project from the sound files in the folder. Audacity projects can only be used by Audacity.
- To make an audio file (such as WAV or MP3) for playing on your music player, or for use in other applications, use one of the Export Audio commands, available from the menu.
Contents
- Structure of an Audacity project
- Saving an Audacity Project
- Saving copies of projects
- Opening an Audacity Project
- Moving or sending an Audacity project
- Backing up Audacity projects
- Deleting an Audacity project
- Autosave and Recovery
- Disk space usage
Structure of an Audacity project
The Audacity Project Format stores all Audacity tracks and clips, labels, amplitude envelope points, gain and pan data, together with other project data. The audio can be a recording, imported files, generated audio or a mixture of any of those. Projects are a convenient way to save your extended multi-track piece and come back to it later exactly as you left off.
Each Audacity project is stored in its own SQLite database with the extension .aup3.
Audacity's project format is not compatible with and cannot be opened in any other audio application.
The structure of a saved Audacity project is:
- An AUP project file - the name of the project followed by ".aup", for example "my_song.aup"
- A _data folder with the same project name and in the same folder as the .aup file, for example "my_song_data"
- Within that _data folder, a sub-folder structure with lots of little AU block files which are individual segments of the audio data.
- Note that default behavior on Windows and Mac is to hide certain file extensions. If this applies, the .aup file will only appear as "my_song" in the computer. On Windows, the .aup extension will be hidden if Audacity was installed from the .exe installer and "Hide file extensions for known file types" remains checked in Windows Explorer. You can unhide extensions on Windows by following these instructions.
The project file describes how Audacity links these AU block files together to make up the clips and tracks in the project. It also contains gain, pan and envelope information, data to manage the waveform display.
The AUP file is in XML format and can be opened in a text editor if required. The AU block files are stored in a lossless, uncompressed format. Their default size is 1 MB or less. This Audacity Project Format is designed to make editing audio faster in Audacity. By updating individual AU block files during editing, Audacity can change audio or move it around in the project without copying large quantities of data from one place to another.
- When importing an uncompressed audio file with the "Read uncompressed file directly from the original (faster)" option checked in Import / Export Preferences never move, rename or delete that file unless you first copy it into the Audacity project. See for more information.
- Never move, delete or rename any of the block files or folders inside the _data folder.
- Never rename the AUP file or the _data folder by hand.
- If you want to rename your project (for example, to save a snapshot at a particular point), use one of the or commands.
- Always keep the AUP file and the _data folder together in the same directory (folder).
Saving an Audacity Project
A saved Audacity Project can only be opened and used by Audacity. If you want an audio file that will play on your music player or to burn a CD, use an Export command.
The benefits of saving an Audacity Project are:
- Saving a project lets you save unfinished work and re-open it later in Audacity exactly as it was, with all edits and recorded/imported tracks preserved. Note carefully that the Undo history is not saved with the project and so the project history starts afresh when you re-open the project later.
- Audio data is always preserved in lossless quality. This is useful if you have already exported to a lossy audio format like MP3 but decide to edit the project further. Editing and re-exporting the project saves the additional quality loss of re-editing the previously exported MP3.
- No need to re-import or re-record files
- Fast loading, even of multiple long tracks
There is no need to Save a project, unless required, as it is possible to work with temporary project files and then just use to export the required audio files. If the project is not saved, the necessary audio data is stored in the temporary folder specified in the Directories section of Preferences until exiting the application. At that point, Audacity offers the choice of saving a project or not.
There are three main commands for saving projects:
- saves a standard project as an AUP3 project file (a file with ".aup3" after its name). If the project does not have any unsaved changes (for example, if you just saved it), "Save Project" will be grayed out.
- similarly saves a standard project as an AUP3 file and _data folder. It is for saving an existing Project to a new name to make a copy of the project in its current state (for example as a staged safety backup copy of your project in a known state) The current project will remain open for you to continue working on it.
- similarly saves a standard project as an AUP file and _data folder. It is for saving an existing Project to a new name to make a copy of the project in its current state (for example as a staged safety backup copy of your project in a known state) The current project will remain open for you to continue working on it.
- similarly saves a standard project. It is useful for saving an empty project or to save an existing Project to a new name. Unlike the Backup Project Audacity will close the current project in its last closed state and open the new project in the current state.
As with saving any type of file, certain characters cannot be used in the name of the AUP3 file if they are reserved for the operating system. See our information on forbidden characters. When saving an Audacity project it is normally easiest to use the command, which has a default shortcut of Ctrl + S (or ⌘ + S on Mac). If you save a project again having made further changes to it, "Save Project" then updates the AUP3 file silently without bothering you with prompts.
Saving copies of projects
Backup Project
Accessed by:
This is the safe and recommended way to make a safety backup copy of a project as you work on it. This could serve either as a single backup copy of the project, or as one of several incremental copies of the project in the state it had at a particular date and time. Unlike "Save As..." using this command will leave your current project open enabling you to continue working on it.
Save Project As
Accessed by:
This is a way to make a copy of a project with a new name or location. If you "Save Project As" with a new name, the project window then displays the project name you just "saved as". The project window displaying the project as previously named is closed in its last saved state, but can be reopened as required.
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You should never use the operating system's copy and paste to make a copy of the project AUP file and _data folder in the same folder as the original project. If you must make a copy by hand, save and close the project first then copy the AUP file and _data folder and paste these into a different folder. This ensures the original file and folder names are retained. |
Opening an Audacity project
When opening an Audacity project always use or to open the "my_project.aup3".
Audio which was not saved as an Audacity Project will need to be imported using or by dragging the file in. The Import command is used to import audio data into an already open project.
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Older Projects
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Missing or orphan block files
Occasionally when a project is opened Audacity will find that there may be some missing data (block files) or some additional extraneous data not needed for the project.
This is normally caused by a system or application crash but sometimes can be down to (as yet undiscovered bugs).
If this happens warning messages will be displayed:
The above links explain the possible remedial actions you can take in these circumstances.
Moving, renaming or sending an Audacity project
Moving or renaming Audacity projects is simple now that Audacity has a unified project structure in a single .aup3file.
- It can be difficult to email complex projects to others because of the size of the project data. Note that ZIP formats do not support reliable character encoding, so for the name of the project, labels, track names or metadata, only use A to Z or a to z characters, whole numbers (0 to 9), underscore or hyphen-minus (or use the NUMPAD_SUBTRACT key).
See also Sending your work to others and this FAQ.
Backing up Audacity projects
Regular backups should if possible be made to one or two devices other than the device the current project is stored on, as computer hard drives can fail, destroying all data. For example, backups could be made to another internal drive on the computer, or ideally to an external USB drive or uploaded to an online (cloud) storage service.
For advice on backing up Audacity projects please see this FAQ.
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If you have just made a recording it is strongly recommended that you immediately export your audio using to WAV or AIFF (ideally to an external drive) as a safety copy before you start editing the project. |
Deleting an Audacity project
There is no File > Delete Project command in Audacity; therefore to delete a project to free up disk space it is necessary to make the deletion manually. You just need to delete the AUP3 file. {{note|This will not remove the listing of your project under . After deleting the project you can choose the AUP3 entry for that project in the Recent Files list in order to remove the entry.
Autosave and Recovery
As soon as you open a project window and change the window contents, whether this is a previously saved project or you are creating a new project, Audacity writes a temporary reference file for that project called an ".autosave" file. This allows Audacity to automatically recover unsaved changes in the event of a crash or power loss.
When you use , or there are no longer unsaved changes, so the ".autosave" file is deleted until fresh unsaved changes are made. The file is stored in the "AutoSave" folder inside Audacity's folder for application data. The file is of identical internal structure to an AUP project file, but is not readable by a text editor.
Most changes you make to the audio data, such as adding or removing audio or applying an effect to it, trigger writing the ".autosave" file. A change to the position of the selection or editing cursor does not write to the ".autosave" file, and is not captured when closing the project, unless the project is already "dirty" (as shown by Save Project in the submenu being not grayed out and being clickable).
Disk space usage
This can be particularly important if you are editing a large project.
Audacity references the original audio material until you actually perform some kind of edit on it, such as cutting a piece away or using any effect on it. So if you a selection, this doesn't actually increase the number of .au files in the _data folder, and doesn't increase disk space usage. for example does increase the number of .au files, but this is so these files can be retained separately on the Audacity clipboard for .
Once you perform an edit, the original unchanged audio is retained, along with the changed audio. This is so you can use and to try out edits and undo them if they do not sound as you wanted.
If you edit just a small selection in a track, only that small selection of changed data is written to disk. Nonetheless, this still represents a doubling of disk space usage for that selection, and a further edit on that selection (unless you first undo the previous edit) adds the same amount again, and so on. For example, a five minute stereo recording at default quality settings takes 100 MB of space. If you edit the whole length of that recording, disk space usage will increase to 200 MB.
If disk space is a problem while working on a project, you can use to discard Undo levels and reclaim disk space. Note that once you close the project by using or exiting Audacity, the audio data needed for Undo/Redo is discarded, so as to make project storage as economical as possible.
Any audio data placed on the Audacity clipboard by Cut or Copy is however retained until you exit Audacity itself.
