You can choose the default branch for a repository. The default branch is the base branch for pull requests and code commits. For more information about the default branch, see "About branches."
Note: If you use the Git-Subversion bridge, changing the default branch will affect your
trunk branch contents and the
HEAD you see when you list references for the remote repository. For more information, see "Support for Subversion clients" and git-ls-remote in the Git documentation.
You can also rename the default branch. For more information, see "Renaming a branch."
To change the default branch, your repository must have more than one branch. For more information, see "Creating and deleting branches within your repository."
On GitHub.com, navigate to the main page of the repository.
In the "Code and automation" section of the sidebar, click Branches.
Under "Default branch", to the right of the default branch name, click .
Use the drop-down, then click a branch name.
Read the warning, then click I understand, update the default branch.