PS before and after

Is there a keyboard shortcut that allows you to toggle where you currently are vs. the file you originally loaded into PS (i.e. a before and after)?

There are several ways....

1. Hold down the ALT key then click on the Visibility icon (the "eyeball") of the Background or original layer. This will turn off the visibility of all the layers above the Background layer allow you to see the original. ALT+click again to turn the layers back on.

2. Press F12 to Revert to Original, then press CTRL+Z to Undo...which will take you back to your last chance.

3. The preferred method is to use Snapshots. Look at the History Panel...at the very top is a small thumbnail of your original image....if you click on it, the original image will be shown. At the bottom of the panel is a Create New Snapshot icon. If you create an snapshot based on your last edit; you can switch between Before and After by simply selecting either of the Snapshots.

As an aside, if you look in the left column of the History Panel, you will see check boxes where the History Brush can be positioned. This allow you to revert to what the image looked like at that particular step.

If you make a duplicate layer of the original before editing you can click take the checkmark out of the duplicate layer to see original then just checkmark it to see the edited version...