- Click on "About this Mac" in the Apple Menu.
- Click on "System Report...".
- On the left side, select "Applications" from the "Software" section.
- On the right side, you can see the applications that are installed on your computer. The fifth column tells you if the application is 64-bit.
"Yes" = 64-bit
"No" = 32-bit
- On the left side, click on "Legacy Software" to see legacy applications.