Installation of AstroImageJ on Mac OSX

This page is to help with installing the latest version of AstroImageJ on the Mac operating systems. The files linked from the server are complete and do not require a previous installation of ImageJ or AstroImageJ, or other software to run.

If you already have installed version 2.0 of AIJ or later, simply use the update option on the AIJ toolbar 'Help' menu to have the most recent version. The user will need write permission to the directory where the software is installed to use this feature.

For more information, help from other users, and to post advice or questions please see the

AstroImageJ user forum on nabble

One-step AIJ installation is not directly compatible with OS X 10.12, 10.13, or 10.14+. There are currently two procedures that are tested to work. The simplest only requires a command to be executed in a terminal window once the package is installed:

  1. Download the latest installation file.
  2. Unzip the installation file and move the AstroImageJ folder to the Applications folder
  3. Run this command in Terminal

  4. xattr -r -d /Applications/AstroImageJ

That's it! AIJ should now start up normally. If it does, then follow the instructions below for what to do after the installation. There is no need to run both methods. We expect the first one will work for most users. However, if it does not, perhaps due to an unexpected change in IOS, you could try this previous workaround that is a bit more complicated and requires superuser login.
  1. If you haven't already, Install AIJ by unzipping the install file and dragging the resulting AstroImageJ folder to the Applications folder.
  2. Open the Terminal app from the /Applications/Utilities/ folder and then enter the following command syntax: sudo spctl --master-disable
  3. Hit return and authenticate with an admin password.
  4. Relaunch System Preferences and go to the Security → Privacy → General tab.
  5. You will now see the Anywhere option under Allow apps downloaded from:. Select this option.
  6. Make a copy of /Applications/AstroImageJ/ on the desktop. An easy way to do that is hold down the alt key while dragging from the /Applications/AstroImageJ folder to the desktop.
  7. Delete the original copy of that is still in the /Applications/AstroImageJ folder.
  8. Drag the copy of from the desktop back to the /Applications/AstroImageJ folder.
  9. Start AIJ and set up your memory settings as needed.
  10. Close AIJ.
  11. After running AIJ the first time, enter the following command syntax to reenable GateKeeper (AIJ will continue to work normally): sudo spctl --master-enable

After installation you should allocate the memory your uses will need, and check for AstroImageJ updates. Both of these can be done at any time, and the updates will keep your installation current with bug fixes and new features.

On the Mac with this installation procedure AIJ can be started by double-clicking either the or the icons. Either app can be dragged to the Dock to provide convenient access for starting AIJ.