Forking a repository is similar to copying a repository, with two major differences:
- You can use a pull request to suggest changes from your user-owned fork to the original repository, also known as the upstream repository.
- You can bring changes from the upstream repository to your local fork by synchronizing your fork with the upstream repository.
You can fork any public repository to your user account or any organization where you have repository creation permissions. For more information, see "Permission levels for an organization."
You can fork any private repository you can access to your user account and any organization on GitHub Team or GitHub Enterprise where you have repository creation permissions. You cannot fork a private repository to an organization using GitHub Free.
You can use GitHub Desktop to fork a repository. For more information, see “Cloning and forking repositories from GitHub Desktop."
Deleting a fork will not delete the original upstream repository. You can make any changes you want to your fork—add collaborators, rename files, generate GitHub Pages—with no effect on the original.
In open source projects, forks are often used to iterate on ideas or changes before they are offered back to the upstream repository. When you make changes in your user-owned fork and open a pull request that compares your work to the upstream repository, you can give anyone with push access to the upstream repository permission to push changes to your pull request branch. This speeds up collaboration by allowing repository maintainers the ability to make commits or run tests locally to your pull request branch from a user-owned fork before merging. You cannot give push permissions to a fork owned by an organization.
Private forks inherit the permissions structure of the upstream or parent repository. For example, if the upstream repository is private and gives read/write access to a team, then the same team will have read/write access to any forks of the private upstream repository. This helps owners of private repositories maintain control over their code.
If you want to create a new repository from the contents of an existing repository but don't want to merge your changes upstream in the future, you can duplicate the repository or, if the repository is a template, use the repository as a template. For more information, see "Duplicating a repository" and Creating a repository from a template".