Undo a Git merge that hasn't been pushed yet

With git reflog check which commit is one prior the merge (git reflog will be a better option than git log). Then you can reset it using:

git reset --hard commit_sha

There's also another way:

git reset --hard HEAD~1

It will get you back 1 commit.

Be aware that any modified and uncommitted/unstashed files will be reset to their unmodified state. To keep them either stash changes away or see --merge option below.


As @Velmont suggested below in his answer, in this direct case using:

git reset --hard ORIG_HEAD

might yield better results, as it should preserve your changes. ORIG_HEAD will point to a commit directly before merge has occurred, so you don't have to hunt for it yourself.


A further tip is to use the --merge switch instead of --hard since it doesn't reset files unnecessarily:

git reset --merge ORIG_HEAD