Thank you, Adobe, for bringing your Undo into the '90s.

[Mobius Strip]

Finally, 20 years after every other application on the planet, Photoshop gets multi-level Undo.

And the fixed-ratio scaling from the corners is another big win for common sense... except that it's not consistent between object types.

Someday we might get "Paste as new image," and be able to load keyboard shortcuts (currently you can save them but not load them).

[Semaphoric]

But "Step Backwards" is the same thing, and has been there for years.

[John Waller]

Reasons for the previous design are in this article

Why Does Adobe Photoshop Differentiate Between "Undo" And "Step Backwards"?

Back in 1997, when they were designing the History feature in Photoshop, there was much internal debate in Adobe about what Ctrl-Z should do: multiple Undo or Before/After toggling. There were people on both sides of the argument.

The winning logic in 1997:

"...felt a certain image analysis behavior in Photoshop was more critical. That behavior being that many photographers and image processing experts used the traditional Undo shortcut behavior to quickly make a change, then toggle back and forth rapidly to see the Before/After effect on the screen. Hitting Cmd-Z with this method helps someone to make a decision about whether the edit they just made is what they wanted."

We now have non-destructive editing and Adjustment Layers so Ctrl-Z is not really needed for Before/After toggling these days. Ctrl-Z = multiple undo is more useful and intuitive. Better late than never.

[Mobius Strip]

Interesting historical note, thanks. But I still think it's flawed, because Redo already existed.

I got tired of remapping Ctrl/Command-Z to be "step backward."

I wonder if they fixed the longstanding (and long-ago-reported) bug where stepping backward inexplicably deselects the layer you're working on, in addition to stepping backward...

Yes, it appears that they did!

I also can't find any way to map "step backward" to a keystroke anymore, not that it matters.

[Trevor.Dennis]

'Ctrl z' (Cmd z) is faster and easier than 'Ctrl Alt z' (Cmd Alt z), so I have, for a very long time, mapped step backwards to a single G-key on my G910 gaming keyboard.  But the irony is that I seldom use this key, as I usually prefer to use the history panel to step back to a specific point.

This sort of workflow works better with a desktop and multiple screens, where you have space to keep all the panels open.

[JJMack]

But I would need to have a special setup for my Logitech G13 keyboard for CC 2019 it was easier to edit CC 2019 Keyboard shortcuts and change the shortcuts to be consistent with my other install versions of Photoshop. CS6, CC 2014 and CC 2018.  My G13 joystick is programmed to scroll the history and layer palettes.  I also use the history panel on my second display so I can quickly step back to where I want to be.

[Mobius Strip]

Which brings us back to the baffling lack of a way to load keyboard shortcuts...

[JJMack]

Yes Adobe change my shortcut keys  when I opened CC 2019 the first time and I saw a message the state that was done to me.  It was vert easy to edit my Keyboard shortcut and delete the three shortcuts in the Application Menu  Edit then assign Ctrl+Z to toggle last state then in Panel Menu History to assign the shortcuts for step backwards and forwards.  Now CS6, CC 2014, CC 2018 and CC 2019 work the same way one my machine.

[Kukurykus]

Wasn't 'multi-level Undo' 'always' avialble together with 'shift' key? I don't like new solution, so I switched to old behaviour.