You can now fork a repo and copy only the default branch

Previously, when creating a fork all branches from the parent repository were copied to the new fork repository. There are several scenarios where this is unneeded, such as contributing to open-source projects. When all branches are copied, it could result in slow repo cloning and unnecessary disk usage. With this new feature, only the default branch is copied; no other branches or tags. This may result in faster clones because only reachable objects will be pulled down.

If you want to copy additional branches from the parent repository, you can do so from the Branches page.

Read more about copying additional branches.

Read more about branches.

Read more about working with forks.