How to Undo Last Git Commit

Sometimes, when working with Git, you may want to undo the latest commit. A commit is a snapshot of a Git repository at a given time. Git has a reference variable called HEAD that points to the latest commit in the current working branch. To undo a commit, all you need to do is point the HEAD variable to the previous snapshot.

This guide explains how to undo the last Git commit.

It is not recommended to undo a commit is already pushed to a shared repository. If you only want to change the commit message, check out this article
.

Git Three-Tree Architecture #

In Git you can undo changes using the git reset command followed by the commit identifier.

git reset takes additional arguments that allow you to control the command behavior. To better understand how reset works let’s talk about the Git’s three different trees. Three-tree architecture is the key concept of the Git management system. They are called trees because they represent collections of files.

Git manages and manipulates the following three trees:

• The Working Directory – A directory, including all subdirectories and files on the local filesys­tem that is asso­ci­at­ed with the repository. It is often referred to as a “working tree”. The working directory is something like a sandbox where you can test the changes before committing them to the staging index.
• The Index – This tree keeps track of new or changed files that have been added to the index with git add, to be included in the next commit. It is often referred to as “staging area” or “staging index”.
• The HEAD – A pointer to your last commit on the current branch.

The git reset command has three arguments that correspond to the three trees:

• --soft – Updates the HEAD pointer to the given commit. The Working directory and Index are not changed.
• --mixed – Updates the HEAD pointer and resets the Index to the specified commit. The Working directory is left untouched. This is the default operation mode of the reset command.
• --hard – Updates the HEAD pointer and resets the Index and the Working directory to the specified commit. Be extra careful when using this option as all local changes you haven’t committed will be overwritten and lost.

Undoing the Last Commit #

To undo the last commit without losing the changes you made to the local files and the Index, invoke git reset with the --soft option followed by HEAD~1:

git reset --soft HEAD~1

HEAD~1 is a variable that points to the previous commit. The command above moves the current branch backward by one commit, effectively undoing your last commit. If you run the git status command, you’ll see that the changed files are listed as uncommitted changes.

To update the HEAD pointer to reset the Index, run git reset with --mixed or without an option:

git reset --mixed HEAD~1git reset HEAD~1

The changed files are kept up, but unlike the previous example, now the changes are not staged for commit.

If you don’t want to keep the changes you made to the files, invoke the git reset command with the --hard option:

git reset --hard HEAD~1

Before performing a hard reset, make sure you don’t need the changes anymore.

Undoing Multiple Commits #

With git reset, you can return to any previous commit.

For example, to move the current branch back three commits, you would use:

git reset --hard HEAD~3

Since we are using --hard, the command above will remove the latest three snapshots from the commit history.

Another way to move back to a specific commit is to pass the commit ID to the git reset command.

Use git log --oneline to find the commit IDs:

git log --oneline

The command will display a list of all commits, including the ID and the first line of the commit message:

32921222 (HEAD -> master) Update changelog
7505724c adding new tests
750862ce new blog post
95a63417 sort configuration file
252032e4 Refactor User class
...

Once you know the ID of the commit you want to reset to, just pass the ID to the git reset command:

git reset --hard 95a63417

Conclusion #

To undo the last commit, use the git reset command. Don’t reset pushed commits as it may potentially cause a lot of problems for your colleagues.

If you hit a problem or have feedback, leave a comment below.