About changing the default branch
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."
You can also rename the default branch. For more information, see "Renaming a branch."
You can set the name of the default branch for new repositories. For more information, see "Managing the default branch name for your repositories," "Managing the default branch name for repositories in your organization," and "Enforcing repository management policies in your enterprise."
To change the default branch, your repository must have more than one branch. For more information, see "Creating and deleting branches within your repository."
Changing the default branch
On your enterprise, navigate to the main page of the repository.
Under your repository name, click Settings. If you cannot see the "Settings" tab, select the dropdown menu, then click Settings.
Under "Default branch", to the right of the default branch name, click .
Select the branch dropdown menu and click a branch name.
Read the warning, then click I understand, update the default branch.