Git HEAD~ vs HEAD^

Before we look at the difference between HEAD~ and HEAD^, let’s look at HEAD without any modifier.

HEAD

The most recent commit on the current branch is the HEAD of the branch. Commands that take a commit as a parameter will use HEAD by default.

git show

is the same as

git show HEAD

You can also use the at sign (@) as a shortcut for HEAD

git show @

HEAD^

The caret (^) represents the commit’s parent.

We can display our log in a readable way with git log --oneline --graph (see How to Improve Git Log).

* d780351 Add LICENSE.txt (HEAD)
* 25b2f97 Add plugin code
* 300d2a9 Add .gitignore
* 20dab1f Initial commit with README.md

Our most recent commit, at the top of the list (HEAD), is Add LICENSE.txt.

To get our second to last commit, the parent of HEAD (second from the top) which has the message Add plugin code, we can use

git HEAD^

The third commit from the top (the parent of the parent of HEAD) can be targeted with

git HEAD^^

Warning: When numbers are used with ^, they do not represent the number of ^s.

HEAD^2 is NOT equivalent to HEAD^^

Using a number with ^ (e.g. HEAD^2) comes into play when you have a git history that includes merge commits and is a topic for another blog post.

HEAD~

The tilde (~) is a shortcut character for when you have multiple carets (^) in a row.

HEAD~3 is equivalent to HEAD^^^

HEAD~5 is equivalent to HEAD^^^^^

If no number is specified, the default used is 1, so

HEAD~ is equivalent to HEAD^

Recommendation

When working with git I often use ~ and almost never use ^. Typically, I use HEAD, HEAD~1, and HEAD~2 and when things get more complicated than that, I target the commit by the unique SHA (e.g. git show 300d2a9).

Sal Ferrarello (@salcode)

Sal is a PHP developer with a focus on the WordPress platform. He is a conference speaker with a background including Piano Player, Radio DJ, Magician/Juggler, Beach Photographer, and High School Math Teacher. Sal can be found professionally at WebDevStudios, where he works as a senior backend engineer.