How To Auto-Delete Temporary Files abandoned by Mozilla apps on your Mac OS X Desktop.
Firefox on Mac OS X does not clean up temporary files in the same way as the Windows version. When you right-click a PDF file and view it (instead of save) Firefox downloads it and then runs the browser helper application. Firefox has no way of knowing when you?ve finished with the file, so by design it does not delete it.
This can leave your desktop cluttered with PDF files and other assorted detritus of the web.
The location for saving temporary files from the Open with command is set by your Safari preferences on the General tab. Change Save downloaded files to? and pick something like Documents | Downloads | Temp. Firefox will now download files there with you chose Open with instead of Save. Your default Save location is still set in Firefox preferences.
Thunderbird also displays this behaviour.
The fix is
- Go the the URL about:config (type it in the address line of Firefox)
- Right/Control-click anywhere on the page and select New > Boolean from the context menu
- Type or paste
browser.helperApps.deleteTempFileOnExitas the preference name in the dialog box that pops up and select True for the value
Firefox will now automatically delete these Temp files when it exits.
For Thunderbird get to the config editor via Thunderbird > Preferences? > General > Config Editor? and add the same Boolean preference.
Update: 21 August 2015 (!) Although I wrote this 8 years ago it still gets traffic and is still an issue for many people. Say thanks below if it helped. A lot of the internet links to this post broke over the last few months, but I’ve fixed it now.
Update: 4 September 2015 Railroad adds that this is still an issue with OS X 10.8.5 through to 10.10.5. Thanks for the update.