How to get back to the latest commit after checking out a previous commit?

I sometimes check out some previous version of the code to examine or test. I have seen instructions on what to do if I wish to modify previous commits -- but suppose I make no changes. After I've done e.g. git checkout HEAD^, how do I get back to the tip of the branch?.. git log no longer shows me the SHA of the latest commit.

Solution 1:

If you know the commit you want to return to is the head of some branch, or is tagged, then you can just

git checkout branchname

You can also use git reflog to see what other commits your HEAD (or any other ref) has pointed to in the past.

Edited to add:

In newer versions of Git, if you only ran git checkout or something else to move your HEAD once, you can also do

git checkout -

to switch back to wherever it was before the last checkout. This was motivated by the analogy to the shell idiom cd - to go back to whatever working directory one was previously in.

Solution 2:

git checkout master

master is the tip, or the last commit. gitk will only show you up to where you are in the tree at the time. git reflog will show all the commits, but in this case, you just want the tip, so git checkout master.