1. Home
  2. Blog
  3. Software Development

Software Development

Git Merge vs Rebase: Differences, Examples and When to Use Each

Git merge vs rebase decides what your project history looks like. See both on the same example with real log output, learn the one rule that prevents disasters and copy a safe team workflow.

7 min read
Git merge vs rebase: differences, examples and when to use each

Key takeaways

  • Merge joins two branches with a new merge commit and keeps history exactly as it happened.
  • Rebase replays your commits on top of another branch, which gives a straight line but new commit hashes.
  • Never rebase commits that other people already pulled.
  • Rebase your own feature branch before opening a pull request, and merge when you bring it into the main branch.

Your feature branch is behind main, and you need the new work. Git merge vs rebase is the choice between two ways of getting it, and both are correct. They differ in what your history looks like afterwards.

We built one tiny repository, ran both commands and pasted the real output below, so you can compare the result instead of imagining it. New to Git? Start with our Git tutorial for beginners.

What git merge and git rebase do

git merge takes the tips of two branches and combines them. If both branches have new commits, Git creates a merge commit with two parents. Nothing that already exists is changed.

git rebase takes the commits unique to your branch, sets them aside, moves your branch to the tip of the other branch and then replays your commits one by one. The replayed commits are new commits with new hashes, even though their changes are the same.

Git merge in practice

Our starting point: commit A on main, two commits (F1, F2) on feature, and one more commit (M1) added to main afterwards. Now we merge main into feature.

git switch feature
git merge main
git log --oneline --graph

*   f507aab Merge main into feature
|\
| * 8842fb5 M1
* | 082cc6a F2
* | 5a71e3c F1
|/
* 8766865 A

The graph shows the real story: two lines of work that were joined. The original commits F1 and F2 keep their hashes. The cost is an extra merge commit, and on a busy project the graph turns into a web.

Git rebase in practice

Same starting point, but this time we rebase feature onto main.

git switch feature
git rebase main
git log --oneline --graph

* 1ff474b F2
* bf9149e F1
* 8842fb5 M1
* 8766865 A

The history is one straight line, as if you had started your work after M1. Look at the hashes: F1 was 5a71e3c and is now bf9149e, and F2 changed from 082cc6a to 1ff474b. Git rewrote them, and that is why rebase needs care.

Merge vs rebase side by side

Aspect Merge Rebase
History shape Branching graph with merge commits One straight line
Existing commits Unchanged Rewritten with new hashes
Conflicts Resolved once, in the merge commit May need fixing for each replayed commit
Safe on shared branches Yes No
Best for Combining finished work into main Updating your own branch before review

Tip: if you cannot decide, ask who else has your branch. If nobody does, rebase is safe. If a teammate has pulled it, merge.

The golden rule of rebasing

Do not rebase commits that exist outside your own repository. After a rebase your branch no longer matches the copy on the server, so pushing needs a force. If a colleague built work on the old commits, their history now disagrees with yours, and sorting that out is painful.

Rebasing your private feature branch is fine. Rebasing main or any branch others use is not.

A safe team workflow

This routine keeps history clean without surprising anyone. It is also what most teams use in front of their CI pipeline, such as the one in our GitHub Actions CI/CD guide.

git switch feature
git fetch origin
git rebase origin/main        # or: git pull --rebase
# fix conflicts, then: git add <file> && git rebase --continue
git push --force-with-lease   # only on your own branch

--force-with-lease refuses to overwrite the server branch if someone pushed to it since you last fetched, which plain --force would silently destroy. When the pull request is approved, merge it into main.

How to undo a bad rebase

A rebase looks destructive, but the old commits stay in Git’s reflog for a while, so you can go back.

git reflog                    # find the commit before the rebase
git reset --hard HEAD@{5}     # example position, check reflog first

Create a backup branch with git branch backup before any risky rebase, and recovery becomes one command. Running a database or tools in containers on the side? See our Docker tutorial for beginners.

Final thoughts

Merge keeps the truth, rebase keeps it tidy. Use rebase to refresh your own branch, use merge to deliver it, and never rewrite history that other people depend on.

Frequently asked questions

What is the difference between git merge and git rebase?

Merge combines two branches with a merge commit and keeps all existing commits. Rebase moves your commits on top of another branch and rewrites them, which produces a linear history.

Should I use merge or rebase?

Rebase your own feature branch to stay up to date, and merge when delivering it into a shared branch such as main. Use merge whenever others share the branch.

Is git rebase dangerous?

It is safe on private branches and risky on shared ones, because it rewrites commit hashes. Use a backup branch and the reflog to recover if something goes wrong.

What does force-with-lease do?

It force-pushes only if the remote branch is still where you last saw it, so you cannot accidentally overwrite a teammate’s new commits.

Does rebase delete my commits?

No. It creates new commits with the same changes, and the old ones remain in the reflog until Git cleans them up.

Keep learning

Work with Stack Quora

Need help with testing, WordPress or SEO?

We help teams ship better software and grow their sites. Tell us what you are working on and we will suggest a clear next step.

Keep reading

More guides on testing, AI & modern development

Enjoyed this article? Pick a topic and jump straight into our newest tutorials.

Artificial Intelligence

LLM Structured Output Explained: Getting Reliable JSON From AI Models

LLM structured output explained with validation we ran in Pydantic: JSON mode and schemas, constrained decoding, the ways model output…

Read article →
DevOps

SSH Keys Explained: How They Work, ssh-keygen, Ed25519 and Safe Habits

SSH keys explained with keys we generated: public vs private keys, ssh-keygen, Ed25519 vs RSA, fingerprints, passphrases, ssh-agent, authorized_keys, config…

Read article →
DevOps

HTTP Caching Explained: Cache-Control, ETag and 304 Responses, With a Live Test

HTTP caching explained with a small server we ran: Cache-Control directives, max-age, no-cache vs no-store, ETag revalidation and 304 responses,…

Read article →
Test Automation

API Contract Testing Explained: Catch Breaking Changes Before They Ship

API contract testing explained with a schema check we ran: what a contract is, consumer-driven contracts, Pact, OpenAPI, which changes…

Read article →
Software Testing

Risk-Based Testing Explained: Score Risks, Build a Matrix and Test What Matters

Risk-based testing explained step by step: identifying risks, scoring likelihood and impact, building a risk matrix, mapping risk to test…

Read article →
Databases & SQL

SQL Constraints Explained: NOT NULL, UNIQUE, CHECK and FOREIGN KEY, Tested

SQL constraints explained with tests we ran: NOT NULL, UNIQUE, CHECK, DEFAULT, PRIMARY and FOREIGN KEY, the NULL loopholes, SQLite's…

Read article →
Databases & SQL

SQL Date Functions Explained: Adding, Comparing and Grouping Dates Without Bugs

SQL date functions explained with queries we ran: adding intervals, month-end surprises, date differences, the BETWEEN trap, grouping by day,…

Read article →
Software Development

Python asyncio Explained: async, await, gather and TaskGroup With Real Timings

Python asyncio explained with code we timed: coroutines, await, gather, TaskGroup, error handling, timeouts, limiting concurrency and the blocking-call mistake…

Read article →
Software Development

Debounce vs Throttle in JavaScript: How They Work, When to Use Each, Tested

Debounce vs throttle in JavaScript explained with timings we measured in Node.js: how each works, simple implementations, leading and trailing…

Read article →
Software Development

Python Context Managers Explained: The with Statement, contextlib and Real Uses

Python context managers explained with code we ran: how with works, __enter__ and __exit__, contextlib.contextmanager, suppress, ExitStack, database transactions and…

Read article →
Artificial Intelligence

LLM Temperature and Top-p Explained: How AI Models Choose Their Next Word

LLM temperature and top-p explained with a simulation we ran: how probabilities are reshaped, what top-p keeps, recommended settings by…

Read article →
DevOps

YAML Explained: Syntax, the Norway Problem and Other Traps We Tested

YAML explained with a parser test: basic syntax, lists and maps, the Norway problem, versions turning into floats, octal zip…

Read article →
DevOps

Cron Jobs Explained: Syntax, Real Schedules and the Mistakes That Break Them

Cron jobs explained with schedules we verified: the five fields, operators, real examples, the day-of-month OR day-of-week trap, environment problems,…

Read article →
Software Testing

Bug Life Cycle in Software Testing: Every Status, Who Owns It and Common Mistakes

The bug life cycle explained: every defect status from New to Closed, who owns each step, rejected, deferred and reopened…

Read article →
Test Automation

Property-Based Testing in Python: Hypothesis Finds the Bugs Your Examples Miss

Property-based testing explained with Hypothesis tests we ran: properties vs examples, strategies, shrinking, the real bugs it found in our…

Read article →
Databases & SQL

SQL Pagination Explained: OFFSET vs Keyset, With a Million-Row Test

SQL pagination explained with a million-row test we ran: LIMIT and OFFSET, why deep pages get slow, keyset (cursor) pagination,…

Read article →
Databases & SQL

SQL EXISTS vs IN: Differences, the NOT IN NULL Trap and Performance

SQL EXISTS vs IN explained with queries we ran: how each works, why NOT IN returns no rows when a…

Read article →
Software Development

Python Logging Explained: Levels, Handlers, Formatters and Mistakes to Avoid

Python logging explained with code we ran: levels, basicConfig quirks, named loggers, handlers and formatters, logger.exception, lazy formatting, duplicate logs…

Read article →
Software Development

JavaScript Map vs Object: Key Differences, Pitfalls and a Benchmark

JavaScript Map vs Object explained with code we ran in Node.js: key types, ordering, the prototype trap, JSON, size, WeakMap…

Read article →
Software Development

Python Type Hints Explained: Annotations, mypy and the Errors It Catches

Python type hints explained with a real mypy run: basic annotations, Optional and unions, TypedDict, Literal, Protocol, generics, Callable, strict…

Read article →
Artificial Intelligence

LLM Tokens Explained: How AI Models Read Text, Count Costs and Fill Context Windows

LLM tokens explained with a tokenizer we ran: how text is split, why counts differ by language and tokenizer, context…

Read article →
DevOps

Semantic Versioning Explained: MAJOR.MINOR.PATCH, Ranges and Release Rules

Semantic versioning explained with code we ran: MAJOR.MINOR.PATCH rules, pre-releases, correct version sorting, caret and tilde ranges, 0.x versions, lockfiles…

Read article →
DevOps

Git Reset vs Revert: How to Undo Commits Safely, With a Tested Example

Git reset vs revert explained with a repository we built: soft, mixed and hard reset, revert commits, reverting merges, recovering…

Read article →
Software Testing

The Test Pyramid Explained: Layers, Ratios and When to Break the Shape

The test pyramid explained: unit, integration and end-to-end layers, sensible ratios, the ice cream cone anti-pattern, the testing trophy and…

Read article →
Test Automation

pytest Fixtures Explained: Scope, yield Teardown, conftest.py and Factories

pytest fixtures explained with a suite we ran: how fixtures work, scopes, yield teardown, conftest.py, factory fixtures, parametrized fixtures, built-ins…

Read article →
Databases & SQL

SQL Upsert Explained: INSERT ON CONFLICT, MERGE and the REPLACE Trap

SQL upsert explained with queries we ran: INSERT ON CONFLICT DO UPDATE and DO NOTHING, the excluded row, conditional updates,…

Read article →
Databases & SQL

SQL LIKE Operator Explained: Wildcards, Case Sensitivity and Performance

The SQL LIKE operator explained with queries we ran: % and _ wildcards, escaping, NOT LIKE and NULL, case sensitivity…

Read article →
Artificial Intelligence

AI Hallucinations Explained: Why Language Models Make Things Up and How to Reduce It

AI hallucinations explained: what they are, why language models produce them, common types, how to reduce them with grounding and…

Read article →
Test Automation

Mocking in Python: unittest.mock, patch and the Mistakes That Make Tests Lie

Mocking in Python with unittest.mock, tested: Mock and return_value, side_effect, patching where a name is used, spec and autospec, mocking…

Read article →
Software Testing

Code Coverage Explained: Line vs Branch Coverage and What 100% Really Means

Code coverage explained with a real coverage.py run: line, branch and condition coverage, reading a report, why 100% coverage can…

Read article →
Artificial Intelligence

What Are AI Agents? How They Work, With a Simple Agent Loop You Can Run

What are AI agents? A plain guide to the agent loop, tools, memory and guardrails, with a small Python loop…

Read article →
Test Automation

TDD vs BDD: Key Differences, One Feature Built Both Ways and When to Use Each

TDD vs BDD explained with one discount feature built both ways: red-green-refactor with code we ran, Given-When-Then scenarios, tools, trade-offs…

Read article →
Software Testing

User Acceptance Testing (UAT): Process, Checklist and Real Examples

User acceptance testing explained: who runs it, how it differs from QA, a seven-step process, a UAT test case template,…

Read article →
Artificial Intelligence

What Are Embeddings? Vectors and Cosine Similarity Explained Simply

What are embeddings? A plain-language guide to vectors, cosine similarity and semantic search, with a small example we ran, common…

Read article →
Test Automation

Flaky Tests: What Causes Them and How to Fix Them for Good

Flaky tests explained with demos we ran: the main causes, how to confirm and diagnose one, proper fixes for timing,…

Read article →
Software Testing

Load Testing vs Stress Testing: Differences, Metrics and k6 Examples

Load testing vs stress testing explained: what each proves, spike and soak tests, the metrics that matter, why averages mislead,…

Read article →