What’s The Difference Between git reset –mixed, –soft, and –hard?

Git is an important tool for version control in software development. Among its numerous commands, git reset is one of the most powerful but also one of the most complex, especially with its different options: –mixed, –soft, and –hard. This article explains these options, their syntax, features, and uses, and provides practical examples to help you understand their differences and use cases.

git reset is a command that undoes changes by moving the HEAD (the current branch reference) to a specified commit. It can affect the staging area (index), the working directory, or both, depending on the option used. The three primary modes of git reset—–mixed, –soft, and –hard—determine how the reset operation impacts these areas.

Overview of git reset

• git reset –mixed: Resets the HEAD and updates the staging area, but leaves the working directory unchanged.
• git reset –soft: Only resets the HEAD, leaving both the staging area and the working directory unchanged.
• git reset –hard: Resets the HEAD, updates the staging area, and resets the working directory to match the specified commit.

Let’s dive into each of these modes in more detail.

Syntax

git reset --mixed <commit>

Uses of git reset –mixed

• Default Mode: If no option is provided, git reset defaults to –mixed.
• Updates Staging Area: Changes the staging area to match the specified commit, effectively un-staging files that were previously staged.
• Preserves Working Directory: Leaves the working directory unchanged, so any modifications remain in your files.

Example

Consider you have a commit history like this:

A -- B -- C (HEAD)

Running the following command:

git reset --mixed B

The result is:

• HEAD points to commit B.
• Staging area matches commit B.
• Working directory contains changes from commit C as un-staged modifications.

Use Case

Use –mixed when you want to keep your working changes but remove them from the staging area. This is useful if you realize the changes should not be staged yet but you still want to continue working on them.

Syntax

git reset --soft <commit>

Uses of git reset –soft

• Updates HEAD Only: Moves HEAD to the specified commit without affecting the staging area or working directory.
• Preserves Staging Area: Keeps changes in the staging area.
• Preserves Working Directory: Leaves the working directory unchanged.

Example

Given a commit history like this:

A -- B -- C (HEAD)

Running the command:

git reset --soft B

The result is:

• HEAD points to commit B.
• Staging area retains changes from commit C.
• Working directory contains changes from commit C.

Use Case

Use –soft when you want to adjust the commit history (e.g., remove the latest commit) but keep all the changes in both the staging area and the working directory, allowing you to commit them again.

Syntax

git reset --hard <commit>

Uses of git reset –hard

• Full Reset: Resets the HEAD, staging area, and working directory to match the specified commit.
• Data Loss: Completely discards all changes in the staging area and working directory, making it impossible to recover them through Git.
• Clean State: Useful for discarding unwanted changes and restoring the repository to a known state.

Example

Given a commit history like this:

A -- B -- C (HEAD)

Running the command:

git reset --hard B

The result is:

• HEAD points to commit B.
• Staging area matches commit B.
• Working directory matches commit B.

Use Case

Use –hard when you want to completely discard any changes in the working directory and staging area and revert to a specific commit. This is often used to undo unwanted changes that are no longer needed.

Understanding the differences between git reset –mixed, –soft, and –hard is crucial for effectively managing your Git repository. Each option serves different purposes, from keeping your working changes while un-staging them, to adjusting your commit history without affecting your files, to fully discarding all changes and resetting to a previous commit.

• Use –mixed when you need to un-stage changes but want to keep them in your working directory.
• Use –soft to keep all changes in the staging area and working directory while moving HEAD to a different commit.
• Use –hard to completely discard changes and reset everything to a specific commit.