Edit>Undo (shortcut: C+z) reverses the most recent editing command. For example, this can be used to restore unintentionally deleted text. More complicated operations, such as a search and replace, can also be undone.

If you undo too many changes, Edit>Redo (shortcut: C+e C+z) can restore the changes again. For example, if some text was inserted, Undo will remove it from the buffer. Redo will insert it again.

By default, the last 100 edits is retained; older edits cannot be undone. The maximum number of undos and whether undos are reset when a buffer is saved can be changed in the Editing pane of the Utilities>Global Options dialog box; see the section called “The Editing Pane”.