2.8. Revert

File->Revert. It does not have a default shortcut.

"Revert" causes the image to be reloaded from disk, so that it will look just like it did the last time it was saved---unless, that is, the file has in the meantime been overwritten by you or some application other than GIMP, in which case the new contents will be loaded. For technical reasons, when GIMP reverts a file, it actually closes the existing image and creates a new image. Because of this, reverting an image is not undoable, and causes the undo history of the image to be lost. GIMP tries to protect you from losing your work in this way by asking you to confirm that you really want to revert the image.