When viewing a file on GitHub, you usually see the version at the current head of a branch. For example:
refers to GitHub’s
hubot repository, and shows the
master branch’s current version of the
The version of a file at the head of branch can change as new commits are made, so if you were to copy the normal URL, the file contents might not be the same when someone looks at it later.
For a permanent link to the specific version of a file that you see, instead of using a branch name in the URL (i.e. the
master part in the example above), put a commit id. This will permanently link to the exact version of the file in that commit. For example:
master with a specific commit id and the file content will not change.
Looking up the commit SHA by hand is inconvenient, however, so as a shortcut you can type y to automatically update the URL to the permalink version. Then you can copy the URL knowing that anyone you share it with will see exactly what you saw.
Tip : You can put any identifier that can be resolved to a commit in the URL, including branch names, specific commit SHAs, or tags!