How Do You Compare Changes Between Two Commits in Git?

Comparing changes between two commits in Git is an essential part of tracking and managing your project’s history. This comparison helps you understand the differences introduced between two points in time, whether you are reviewing your own work or examining contributions from others.

Why Compare Changes Between Two Commits?

Understanding the differences between commits allows you to:

  • Identify specific changes made to the codebase.
  • Review and audit code modifications for quality and correctness.
  • Resolve conflicts by understanding the exact differences between branches.

How to Compare Two Commits in Git

Git provides several ways to compare commits. The most common method is using the git diff command. Below are the steps to perform a comparison:

Using the Command Line

To compare two commits, use the following command:

git diff <commit1> <commit2>

Replace <commit1> and <commit2> with the actual commit hashes or references (like branch names or tags). This command will display the differences in the files between the two commits.

Understanding the Output

The output of git diff shows the changes line by line. Lines beginning with a minus (-) indicate deletions, while lines beginning with a plus (+) indicate additions. The comparison is done on a per-file basis, making it easy to track changes across the entire project.

Comparing Commit History

If you want to see a summary of changes between two commits, you can use:

git log <commit1>..<commit2>

This command will display all the commits between <commit1> and <commit2>, allowing you to see a high-level overview of the changes.

Tools to Visualize Git Differences

In addition to the command line, several GUI tools can help visualize differences between commits, such as:

  • GitKraken
  • SourceTree
  • Visual Studio Code’s Git integration

Conclusion

Comparing changes between two commits is a crucial aspect of Git’s functionality. Whether through the command line or a graphical interface, understanding these differences helps maintain the integrity and quality of your codebase.