Github – ToC or Sidebar in GitHub Wiki

You have to add the original repository (the one you forked) as a remote.

From the GitHub documentation on forking a repository:

Once the clone is complete your repo will have a remote named “origin” that points to your fork on GitHub.
Don’t let the name confuse you, this does not point to the original repo you forked from. To help you keep track of that repo we will add another remote named “upstream”:

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

# then: (like "git pull" which is fetch + merge)
$ git merge upstream/master master

# or, better, replay your local work on top of the fetched branch
# like a "git pull --rebase"
$ git rebase upstream/master

There's also a command-line tool (hub) which can facilitate the operations above.

Here's a visual of how it works:

See also "Are Git forks actually Git clones?".

Update Apr. 2021: there are a few tools created by the community that can do this for you:

• Download Directory (Credits to fregante)
  • It has also been integrated into the excellent Refined Github chrome extension as a button in the Github web UI.
• GitZip (Credits to Kino - see his answer here)
• DownGit (Credits to Minhas Kamal - see his answer here)

Note: if you're trying to download a large number of files, you may need to provide a token to these tools to avoid rate limiting.

Original (manual) approach: Checking out an individual directory is not supported by git natively, but Github can do this via SVN. If you checkout your code with subversion, Github will essentially convert the repo from git to subversion on the backend, then serve up the requested directory.

Here's how you can use this feature to download a specific folder. I'll use the popular javascript library lodash as an example.

1. Navigate to the folder you want to download. Let's download /test from master branch.

2. Modify the URL for subversion. Replace tree/master with trunk.

   https://github.com/lodash/lodash/tree/master/test ➜

   https://github.com/lodash/lodash/trunk/test

3. Download the folder. Go to the command line and grab the folder with SVN.

svn checkout https://github.com/lodash/lodash/trunk/test

You might not see any activity immediately because Github takes up to 30 seconds to convert larger repositories, so be patient.

Full URL format explanation:

• If you're interested in master branch, use trunk instead. So the full path is trunk/foldername
• If you're interested in foo branch, use branches/foo instead. The full path looks like branches/foo/foldername
• Protip: You can use svn ls to see available tags and branches before downloading if you wish

That's all! Github supports more subversion features as well, including support for committing and pushing changes.