---
title: Mergify Rebase Command
description: Rebase a pull request.
---

The `rebase` command provides users with an instant method to instruct Mergify
to rebase a pull request against its base branch. It's a handy way to ensure
that the pull request is updated with the latest changes from the base branch
without manually triggering a rebase.

The `rebase` command lets developers keep their pull requests up-to-date and
maintain a clean commit history.

<RebaseAdvantage />

:::caution
  Rebasing a pull request that comes from a fork is deprecated. Use the
  [`update` command](/commands/update) on fork pull requests instead.
:::

## Syntax

To make use of the `rebase` command, simply comment on the desired pull
request:

```text
@mergifyio rebase
```

<Image src={rebaseScreenshot} alt="Posting '@mergifyio rebase' in GitHub interface"/>

## Impersonation

Mergify pushes the rebased branch as a GitHub user, not as itself. Unless a
[`bot_account`](/configuration/data-types#bot-account) is configured, that user
is whoever posted the command, and that account must have signed in to the
[Mergify dashboard](https://dashboard.mergify.com) at least once. If it has
not, the command fails with `Mergify can't impersonate`.

A fork's head branch lives in another repository, and Mergify can only
force-push the rewritten branch there as the impersonated user, which is why
the command is deprecated for fork pull requests. When the fork is private,
`rebase` cannot run at all: GitHub does not let an app modify the head branch
of a pull request opened from a private fork.

The [`update` command](/commands/update) merges the base branch instead of
rewriting the head branch, and impersonates nobody unless you configure a
`bot_account`, so it keeps working on pull requests opened from a fork.