Git Merge vs Git Rebase: Key Differences and When to Use Each

Both git merge and git rebase combine changes from one branch into another, but git merge creates a new commit preserving history, while git rebase rewrites history by moving commits to a new base. Use merge to keep a clear branch history and rebase to create a linear, cleaner history.

Quick Comparison

This table summarizes the main differences between git merge and git rebase.

Factor	git merge	git rebase
History	Preserves full branch history with merge commits	Rewrites history to create a linear sequence
Commit Structure	Creates a new merge commit	Moves commits to a new base without merge commits
Conflict Resolution	Conflicts resolved once during merge	Conflicts may need resolving at each commit during rebase
Use Case	Combining completed feature branches	Updating feature branch with latest main branch changes
Effect on Shared Branches	Safe for shared branches	Can cause problems if rebasing shared branches
Resulting Log	Shows branch structure clearly	Shows a straight, linear history

Key Differences

git merge combines two branches by creating a new commit that ties their histories together. This keeps the full history intact, showing when branches diverged and merged. It is safe to use on branches shared with others because it does not rewrite existing commits.

git rebase, on the other hand, moves your branch's commits to start from a new base commit, effectively rewriting history. This creates a cleaner, linear history without merge commits, which can make the project history easier to read. However, because it changes commit hashes, rebasing shared branches can cause confusion and conflicts for others.

In summary, merge preserves the true history and is safer for collaboration, while rebase cleans up history for clarity but should be used carefully when working with others.

Code Comparison

Here is how you combine a feature branch into the main branch using git merge.

bash

git checkout main
git merge feature-branch

Output

Updating abc1234..def5678
Merge made by the 'recursive' strategy.
 file.txt | 2 ++
 1 file changed, 2 insertions(+)

Git Rebase Equivalent

Here is how you update your feature branch with the latest changes from main using git rebase.

bash

git checkout feature-branch
git rebase main

Output

First, rewinding head to replay your work on top of it...
Applying: Added new feature

Successfully rebased and updated refs/heads/feature-branch.

When to Use Which

Choose git merge when: you want to preserve the full history of how branches combined, especially on shared branches or when the branch history is important for understanding the project timeline.

Choose git rebase when: you want a clean, linear history without merge commits, typically when updating your feature branch with the latest changes from the main branch before merging it back.

Always avoid rebasing branches that others are using to prevent conflicts and confusion.

Key Takeaways

Use git merge to combine branches while preserving full history and merge commits.

Use git rebase to create a clean, linear history by moving commits onto a new base.

Avoid rebasing branches that are shared with others to prevent conflicts.

Merge commits clearly show branch structure; rebasing hides it for simplicity.

Choose merge for collaboration safety and rebase for cleaner personal branch history.