Comparing file versions between different branches

Question

How can one compare the version of a single file between two different branches in IntelliJ IDEA? Rather than comparing two different files/folders.

Answer

To compare a single file in two different branches within IntelliJ IDEA, follow these steps:

1. Open your project and navigate to the branch containing the file (e.g., Branch A). You can switch branches using the Git tool window or the VCS Git Branches menu.
2. In the Project tool window, locate the desired file.
3. Right-click on the file, and from the context menu, navigate to Git > Compare with Branch or Tag....
4. From the dialog that appears, select the target branch (e.g., Branch B) you want to compare the file against. Confirm your selection to proceed.

The IDE will open a diff view showing the differences between the file in Branch A and Branch B. The currently checked-out branch will be labeled "Local," and the comparison will show the respective changes distinctively.

For more details, you can refer to the JetBrains help topic on comparing files and folders.