Update a Forked GitHub Repository

This post is going to illustrate how to sync a fork of a repository to keep it up-to-date with the upstream repository.

Configure an Upstream Remote

Before you can sync your fork with an upstream repository, you must configure a remote that points to the upstream repository in Git.

1. List the current configured remote repository for your fork.

   $ git remote -v
   > origin  https://github.com/YOUR_USERNAME/YOUR_FORK.git (fetch)
   > origin  https://github.com/YOUR_USERNAME/YOUR_FORK.git (push)
   

2. Specify a new remote upstream repository that will be synced with the fork.

   $ git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
   

3. Verify the new upstream repository you've specified for your fork.

   $ git remote -v
   > origin    https://github.com/YOUR_USERNAME/YOUR_FORK.git (fetch)
   > origin    https://github.com/YOUR_USERNAME/YOUR_FORK.git (push)
   > upstream  https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git (fetch)
   > upstream  https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git (push)
   

Fetch from Upstream Repository

1. Direct to the project folder locally
2. Fetch the branches and their respective commits from the upstream repository. Commits to master will be stored in a local branch, upstream/master.

   $ git fetch upstream
   > remote: Counting objects: 75, done.
   > remote: Compressing objects: 100% (53/53), done.
   > remote: Total 62 (delta 27), reused 44 (delta 9)
   > Unpacking objects: 100% (62/62), done.
   > From https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY
   >  * [new branch]      master     -> upstream/master
   

3. Check out your fork's local master branch

   $ git checkout master
   > Switched to branch 'master'
   

4. Merge the changes from upstream/master into your local master branch. This brings your fork's master branch into sync with the upstream repository, without losing your local changes.

   $ git merge upstream/master
   > Updating a422352..5fdff0f
   > Fast-forward
   >  README                    |    9 -------
   >  README.md                 |    7 ++++++
   >  2 files changed, 7 insertions(+), 9 deletions(-)
   >  delete mode 100644 README
   >  create mode 100644 README.md
   

   If your local branch didn't have any unique commits, Git will instead perform a "fast-forward":

   $ git merge upstream/master
   > Updating 34e91da..16c56ad
   > Fast-forward
   >  README.md                 |    5 +++--
   >  1 file changed, 3 insertions(+), 2 deletions(-)
   

   You may also use --no-ff to merge without Fast-forward.

Push to Remote Repository

git push origin master