GitHub · Pull requests · Branches · Checked October 27, 2026

GitHub: changing the base branch of a pull request

The base branch of an open pull request is changed next to its title: click Edit title, select another branch in the base branch drop-down menu, read the information about changing it, and click Change base. GitHub warns that some commits may be removed from the timeline, and that review comments may become outdated because the lines they referenced may no longer be part of the changes in the pull request (GitHub's changing the base branch of a pull request, checked October 27, 2026).

PATCH /repos/OWNER/REPO/pulls/NUMBER
{"base": "BRANCH-NAME"}

Why the base does not change

A branch of another repository: in GitHub's REST endpoint for updating a pull request, base should be an existing branch of the repository the pull request is in; the base branch cannot be updated to point to another repository.
No access: updating a pull request in a public repository takes write access to the head or source branch, and in a repository owned by an organization, membership of that organization. The documented answers to the PATCH are 200, 403, and 422 when validation failed or the endpoint has been spammed; see refused updates to a pull request.
It changed by itself: when a head branch is deleted after its pull request was merged, GitHub changes the base branch of the open pull requests in the same repository that were based on it to the merged pull request's base branch. See branches after merging.

What changes with the base

The comparison: the pull request compares its changes against the branch you selected.
The timeline: some commits may be removed from it.
Review comments: they may become outdated, because the line of code a comment referenced may no longer be part of the changes. See outdated comments.
The base commit: GitHub's documentation adds that when you open a pull request, GitHub sets the base to the commit that branch references, and does not update the base branch's commit if the branch is updated later.

What to do

Pick a branch of the same repository: change it from Edit title, or send the PATCH with base set to an existing branch of that repository.
Behind the new base: update the pull request branch from the merge section with Update branch, which merges the base branch into it, or with Update with rebase; you may not be able to use Update branch if the head branch is protected (GitHub's keeping your pull request in sync with the base branch). See updating the branch.
Conflicts with the new base: resolve them before updating the branch. See merge conflicts.

GitHub pull requests in IntelliJ IDEA

Pull Request Inbox for GitHub, a plugin by Lesstep for JetBrains IDEs 2024.1 or later, shows a pull request's reviews, checks and conversations next to the diff, and merges it with the methods the target branch allows. It sets the base branch when it creates a pull request, and does not change the base branch of an open one: change it on GitHub. Its merge checks name the current base branch, and say when it has new commits or conflicts with the pull request. The review inbox, diffs and conversations are free; approving, commenting, resolving and merging are Pro (US$1.50 a month, with a 30-day trial).

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