Fork a Repository and Contribute to Open Source on GitHub

Forks let anyone contribute to any public project on GitHub. In this lesson you will fork a repository, set up origin and upstream, open a pull request to the original project, keep your fork in sync and find a good first open-source contribution.

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🍴 What Is a Fork?

A fork is your own copy of someone else’s repository, under your GitHub account. You have full write access to your fork, even though you cannot push to the original project. Forks are how anyone can contribute to open source:

1. Fork the project.
2. Make changes in your fork.
3. Open a pull request from your fork back to the original project.

	Clone	Fork
Where the copy lives	Your computer	Your GitHub account
Needs write access to the original to push	Yes	No
Used for	Working on repositories you can push to	Contributing to projects you cannot push to

In practice you fork on GitHub, then clone your fork to your computer.

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🧭 The Fork Workflow Step by Step

1. Fork on GitHub

Open the project’s page and click Fork (top right). Keep the name, optionally untick “Copy the main branch only”, and click Create fork.

2. Clone your fork and add upstream

git clone git@github.com:your-username/project.git
cd project
git remote add upstream https://github.com/original-owner/project.git
git remote -v

origin    git@github.com:your-username/project.git (fetch)
origin    git@github.com:your-username/project.git (push)
upstream  https://github.com/original-owner/project.git (fetch)
upstream  https://github.com/original-owner/project.git (push)

origin is your fork; upstream is the original project (remotes).

3. Create a branch for your change

git switch -c fix/typo-in-readme
# make the change
git add README.md
git commit -m "Fix typo in installation steps"
git push -u origin fix/typo-in-readme

4. Open the pull request

GitHub shows Compare & pull request on your fork. Check that the base repository is the original project (and its main) and the head repository is your fork and branch. Write a clear description, reference the issue (Fixes #123), and submit.

5. Respond to review

Maintainers may ask for changes. Push more commits to the same branch; the PR updates automatically (code review).

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🔄 Keep Your Fork Up to Date

The original project keeps moving. Sync your fork before starting new work:

git switch main
git fetch upstream
git merge upstream/main        # or: git rebase upstream/main
git push origin main

Or click Sync fork on your fork’s GitHub page, then git pull locally. To update a feature branch: git rebase main (then git push --force-with-lease), as in git rebase.

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⚡ Shortcut with the GitHub CLI

gh repo fork original-owner/project --clone    # fork, clone and add upstream in one step
gh pr create --fill                             # open a PR to the original repository

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🌍 Finding Your First Open-Source Contribution

• Look for issues labelled good first issue or help wanted (search label:"good first issue" on GitHub).
• Start small: documentation fixes, typos, examples, missing tests.
• Testers have a natural advantage: reproducing bugs, writing failing tests, and improving test coverage are valuable contributions.

Before you start

File	Why read it
README.md	How to set up and run the project
CONTRIBUTING.md	How the maintainers want contributions: branch names, commit style, tests
CODE_OF_CONDUCT.md	Community behaviour rules
Open issues and PRs	Avoid duplicating work; comment on an issue before starting a big change

Some projects require a CLA (Contributor License Agreement) or a DCO sign-off (git commit -s adds a “Signed-off-by” line). The PR checks will tell you.

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📝 Assignment

1. Fork any public repository (for example a practice repository from a friend, or GitHub’s own example projects) and clone your fork.
2. Add the original repository as upstream and confirm with git remote -v.
3. Create a branch, fix a typo or improve a README, push it and open a pull request to the original repository (or to your own second repository if you prefer not to contact maintainers yet).
4. Sync your fork’s main with upstream using the commands above and with the Sync fork button.
5. Find three issues labelled “good first issue” in projects related to testing or Playwright.

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❓ FAQ

🤔 What is a fork in GitHub?

A copy of another user’s repository in your own GitHub account, which you can change freely and use to propose changes back with a pull request.

🤔 What is the difference between fork and clone?

A fork is a server-side copy on GitHub under your account. A clone is a local copy on your computer. You usually fork first, then clone your fork.

🤔 How do I keep my fork updated?

Add the original as upstream, then git fetch upstream, git merge upstream/main on your main branch and git push origin main, or use Sync fork on GitHub.

🤔 How do I contribute to open source on GitHub?

Find an issue, read CONTRIBUTING.md, fork the repository, make the change on a branch, push it to your fork and open a pull request to the original project.

🤔 Can I make a pull request without forking?

Only if you have write access to the repository; then you push a branch directly and open the PR from it.

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🎯 Next Steps

• 🗂️ GitHub Issues, Labels and Projects
• 📝 Markdown and Writing a Great README
• 📘 Git and GitHub Tutorial: full course