In collaborative software projects, it is common to face the following situation:
a feature branch was created some time ago, work was done on it, and meanwhile the main branch continued to evolve. When the developer returns to finish or submit the work, the question arises:

Should I rebase the existing branch, or should I create a new branch and merge the old one into it?

This article explains the trade-offs and presents a clean, technically sound approach.

The Core Problem: Branch Aging

A feature branch becomes outdated when:

• The main branch receives new commits.
• The feature branch remains inactive or partially completed.
• Both branches modify overlapping areas of the codebase.

This leads to three risks:

1. Merge conflicts
2. Integration surprises
3. Noisy or misleading commit history

The goal is to integrate the feature with minimal friction and maximal clarity.

Option 1: Rebasing the Existing Feature Branch
What rebasing does

Rebasing takes the commits from your feature branch and reapplies them on top of the current state of the main branch.

Conceptually:

main:    A --- B --- C
feature:        D --- E

After Rebase:

main:    A --- B --- C
feature:                D' --- E'

The feature commits now appear as if they were created after the latest changes in main.

Advantages

• Linear, clean commit history
• No extra merge commits
• Clear pull request diff
• Conflicts are resolved once, before review

When rebase is appropriate

Rebasing is the correct choice when:

• The feature branch is used by a single developer
• The branch has not been merged yet
• You want a clean and readable history
• You are comfortable resolving conflicts locally

In practice, this is the most common and recommended case.

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Option 2: Creating a New Branch and Merging the Old One

Another approach is to:

1. Create a new branch from the updated main branch
2. Merge the old feature branch into the new one

What this produces

• An additional merge commit
• The same conflicts you would have had during a rebase
• A more complex history with little added value

Drawbacks

• No reduction in conflict complexity
• Less readable history
• More branches to manage
• Pull requests become harder to review

This approach does not eliminate the underlying integration work. It only postpones or obscures it.

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When a New Branch Does Make Sense

There are specific cases where creating a new branch is justified:

• The original branch contains experimental or discarded commits
• The branch is shared with other developers and rewriting history is unsafe
• Only a subset of commits should be preserved

In these cases, selectively applying commits to a fresh branch is a deliberate cleanup strategy, not a default workflow.

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A Practical Recommendation

For a typical feature that was developed in isolation and needs to be synchronized with an updated main branch:

• Rebase the existing feature branch onto main
• Resolve conflicts locally
• Verify the result
• Open the pull request
• Delete the branch after merge

Then, for the next task:

• Start a new branch from the updated main
• Keep it short-lived and focused

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Final Thoughts

Rebasing is not about preference or style.
It is about reducing integration friction and maintaining clarity.

Creating new branches unnecessarily adds noise without solving the real problem.
A disciplined use of short-lived branches and rebasing before review leads to:

• Faster reviews
• Fewer surprises
• Cleaner project history

In most cases, rebasing the existing feature branch is the simplest and most correct solution.