How to fork and clone an open source repository correctly

Fork vs Clone

A fork is a server-side copy of a repository under your GitHub account. A clone is a local copy on your machine. You need both to contribute to a project you do not have write access to.

The Setup

# 1. Fork via GitHub UI, then clone YOUR fork
git clone https://github.com/YOUR_USERNAME/PROJECT.git
cd PROJECT

# 2. Add the original repo as upstream
git remote add upstream https://github.com/ORIGINAL_OWNER/PROJECT.git

# 3. Verify remotes
git remote -v
# origin    https://github.com/YOUR_USERNAME/PROJECT.git
# upstream  https://github.com/ORIGINAL_OWNER/PROJECT.git

Keeping Your Fork Synced

Your fork immediately goes stale after you create it. Before starting any new work, sync with upstream:

git fetch upstream
git checkout main
git merge upstream/main
git push origin main

This workflow ensures you always branch off current code. PRs built on stale branches require rebasing -- extra work that frustrates maintainers.

For large repos where you only need recent history, use git clone --depth=1 to fetch a shallow clone. This dramatically reduces download size and time.

Working With Shallow Clones

For repositories with long histories -- some go back 15+ years -- a full clone can take minutes and consume gigabytes. Use git clone --depth=1 to fetch only the latest snapshot. This dramatically reduces download size. When you need history later, deepen selectively: git fetch --deepen=50. Most contribution workflows only need recent history, so shallow clones are practical for the majority of open source work.