How to set up git mergetool

1. Download and install DiffMerge

2. Find and open your .gitconfig file. If you installed Git using GitHub for windows then it should be in C:\Users\your_user_name\.gitconfig.

3. Append the following:

[merge]
    tool = diffmerge
[mergetool "diffmerge"]
    cmd = \"C:\\Program Files\\SourceGear\\Common\\DiffMerge\\sgdm.exe\" --merge --result=\"$MERGED\" \"$LOCAL\" \"$BASE\" \"$REMOTE\"
        trustExitCode = true
        keepBackup = false

Adjust the exe file path if it has changed since version 3.3.2 or you have the 32bit version on a 64bit machine.

4. When a conflict happens after a pull or merge, just type git mergetool at the command prompt and you'll get diffmerge all up in your grill. The left column is your version, the right colum is the remote version, and the center column is the result of the merge. Complete the merge, save and close. No other git commands are required after closing.

5. That is all.

ps. you can use any diff tool you want - just adjust the config accordingly.