Balsamiq for Desktop Docs > Autosaving
By default, Mockups 3 for Desktop will automatically save any changes you make. This ensures that you will never lose any work.
Mockups 3 for Desktop automatically saves in two places. First, it commits all changes in real time to the internal backup file. Then after a short period of inactivity, Mockups 3 for Desktop will commit the changes to your original project file. This delay should help when you're saving to a networked drive or folder.
If you find that the autosave feature is causing you problems or your workflow is better suited by manually saving, this is how you would disable it.
In the Project drop down menu, you will find an item named Auto Save Every Change. If that menu item has a check mark next to it, that means autosave is enabled. Clicking on it will disable autosave.
While autosave is disabled, your changes will only be committed to your original project file when you manually save them, either via the Project > Save menu option, or by using the keyboard shortcut (CMD+S on OS X and CTRL+S on Windows).
Your changes are still being saved to the internal backup file, and they will automatically recover if you close Mockups without remembering to save.
In the event you want to discard any changes you have made to the file, you can use the Project > Reload from Disk... menu item to revert to the last thing you saved to your original project file.
To re-enable Mockups 3 for Desktop's autosave feature, simply click the Project > Auto Save Every Change menu item. A checkmark will appear and you should see a confirmation dialog in the lower right corner of the canvas.