REAPER Audio Workflows

How to use REAPER's undo history to get back an edit you lost

By StudioRescue Editorial

Published October 22, 2026

Most people meet REAPER's undo the same way: something goes wrong, they press Ctrl+Z a few times, something else goes wrong, they press it a few more times, and now they are somewhere they did not mean to be with no clear way back. The problem is not that undo is weak. It is that pressing the shortcut repeatedly gives you no view of where you are in the history or how far you have moved.

REAPER keeps that view in a window most beginners never open. It lists the undo points as a sequence you can read and click, and it can remember more than one version of what happened after a given point. Here is how to use it, and what it will not rescue.

Where the undo history window is

It is in the Edit menu, listed as Undo History. This trips people up often enough to be worth saying plainly, because a lot of DAWs put a history panel under View and people go looking there first.

Three ways in, all equivalent:

• Edit, Undo History from the main menu.
• Ctrl+Alt+Z on Windows and Linux. On macOS the official guide's modifier mapping is Ctrl to Command and Alt to Option, so the same command is Cmd+Option+Z.
• Right-click the undo or redo arrow in REAPER's main toolbar. Both arrows open the undo history on a right-click, which is the fastest route if you are already reaching for them.

The shortcut and the menu entry both toggle the window, so the same keystroke closes it again. It can also be docked, through Dock/undock the undo history in the docker on its right-click menu, which is worth doing if you are in a long editing session.

Jumping back to an earlier state

The same right-click menu offers Remove selected state(s) from undo history, and it will act on a selection of several actions at once. It is there for housekeeping, not for fixing a mistake. Removing states throws away routes back, so leave it alone while you are still trying to recover something.

The part most people miss: more than one redo path

This is the feature that makes the window genuinely worth learning. In Options, Preferences, General, Undo there is an option to store multiple redo paths where possible. With it on, going back to an earlier point and then doing something new does not necessarily destroy the work that came after the original point. REAPER stores the new sequence as an alternate set and remembers both paths independently. Every time you return to that point and branch again, another path is created.

You can see it in the list: an action that has been branched from is flagged with a count, so an entry marked (*2) has two additional undo paths stored beyond the original sequence. Right-clicking there lets you choose which of those states to load.

In practice this means you can try an alternate edit of a section without committing to it, which is the same instinct behind keeping several passes when you comp vocal takes in REAPER, except at the level of project edits rather than audio. If you intend to work that way, check the option is enabled before you start rather than after you need it.

Making the history survive closing the project

By default an undo history is only as useful as your current session. Two settings on the same preferences page change that:

• Save undo history with project files. When this is on, REAPER writes the history out alongside the project.
• Allow load of undo history. This is the matching permission to read it back in. The guide is explicit that with both enabled, the undo history is available next time you use the project, even if you have closed and restarted REAPER since.

There is a simple way to check whether it worked, and it does not involve any menus. Saving the undo history produces a separate file next to the project, with the extension .RPP-UNDO, documented as the Undo History File and created only when that option is enabled. Open your project folder and look. If your project is song.RPP and there is no song.RPP-UNDO beside it, the option was not on when you last saved, and there is nothing on disk to load.

The undo settings worth checking

All of these live in Options, Preferences, General, in the Undo settings section. Rather than listing defaults, which vary by version and by whatever you changed two years ago and forgot, open the page and read your own.

What the undo history will not do

This is a record of edits to a project. It is not a backup, and it is worth being clear about the edges.

• It will not bring back a media file you deleted or moved on disk. Undo tracks what you did inside the project, not the files the project points at. If items are showing as offline, that is a different fault with a different fix: see how to fix media offline in REAPER.
• It will not recover a history that was never written. With Save undo history with project files off, there is no .RPP-UNDO file, so once the project is closed the history is gone. No setting changed afterwards brings it back.
• It will not contain changes you told it not to record. If the options covering item, track, envelope point, time selection or cursor position changes are unticked, those changes do not become undo points, so they will not appear in the list.
• It will not help if the project file itself is the problem. A project that refuses to open, or a REAPER that went down mid-session, is a recovery job rather than an undo job. That is covered in how to recover a crashed or lost REAPER project.
• It is not version control. A saved undo history is one file beside one project, and it is overwritten as you work. If you need to compare last week's arrangement with today's, save dated copies of the project instead.

If the state you want is not in the list

1. Check which project tab you are in. Undo history is per project, and REAPER will happily hold a large number of project tabs open at once. Pressing Ctrl+Z in the wrong tab undoes the wrong project's work, and the history you are reading belongs to whichever tab is in front.
2. Look in the project folder for the .RPP-UNDO file. Present means there is a saved history to load. Absent means the option was off, and the question is settled.
3. Check whether the action creates an undo point. Selection and cursor movements are optional entries, so if you were expecting to step back through them and they are not there, that is the setting rather than a fault.
4. Consider that the buffer filled. If you have been editing hard for hours and the oldest states have vanished from the top of the list, the memory ceiling is the likely reason.
5. If the change you want back is a single word or phrase in a take, undoing may be the long way round. Re-recording that one spot is often faster and cleaner: see how to punch in and fix one word in REAPER.