Part 3—Download and Install Software

Step 1 Download and Install ImageJ Software

ImageJ is in the public domain. It can be freely downloaded and installed on any computer including those at schools, homes, and businesses.
  1. Go to the ImageJ Download page and open it in a new window.
  2. Click the link that appears directly below the name of your computer's operating system (e.g., Mac, Linux, Windows). This action will transfer a compressed file of the software to your computer. Your browser should automatically expand the file, creating an ImageJ folder on your computer's hard drive.
  3. For more detailed instructions from the ImageJ website, click Installation Instructions, then select your operating system.
Note to Windows Users: It is recommended that you install ImageJ in the Documents directory, rather than in the Program Files directory. For security reasons, Windows 7 and Windows Vista do not allow programs to alter themselves by writing files to the Program Files directory. If ImageJ is installed in the Program Files directory, then the update function in Step 2 below will not work properly. In addition, if you are a Windows Vista user, be sure to choose the correct version of ImageJ (either 32-bit or 64-bit) for your computer.

Step 2 Update or Downgrade ImageJ

ImageJ Updater Window ImageJ update dialog box.

Double-click the ImageJ icon ImageJ Icon Small to launch the application and choose Help > Update > ImageJ.... A window will appear, telling you the version you are currently running and a list of upgrade versions. Choose the version you want to upgrade to (usually the most recent, or default version) and click OK. After the update downloads, you will need to re-launch ImageJ to run the new version.


ImageJ Updater Window Options ImageJ update dialog box showing upgrade and downgrade options.

ImageJ is a professional research and analysis tool, and is under constant development. If the latest update of the application introduces new bugs or errors, or has an unfamiliar interface that does not match written instructions, you can downgrade your copy of ImageJ to an older, more stable or familiar version.