A lot of the apps around your Mac—like Pages, Numbers, and Preview, for example—are actually tracing your steps. Not in a bad way, though! What I mean is that every time you choose File > Save or press Command-S when you’re working on a document, the app is saving a version of your file, which you can then revert to if you find you don’t like the changes you’ve made. But by default, reverting replaces the file you’re working on, which isn’t always the best thing, to say the least. Here’s how it works and what you can do instead!
So let’s pretend I’ve got this cool (?) circled mountain picture I’m working on in Preview.
Most amazing demonstration file ever, right? Anyway, since I’ve saved this document several times, I can go back to the different save points by using the menu option File > Revert To.
With that, you can either choose the last opened version to restore if that choice is available, or you can select “Browse All Versions” as I’ve done, which’ll take you to a Time Machine–like interface and show you every available file version.
I’ve called out the “Restore” button there, but you’ll want to first search back through the versions by clicking through the windows on the top (highlighted in yellow in my screenshot above) or by using the arrows on the right-hand side. When you’re within that restore mode, there’s also a little bar on the right that’ll let you scroll by date and time and then navigate to that desired version by clicking there.
In any case, though, when you find what you want, clicking “Restore” will overwrite the existing file you’ve got open, as I mentioned, and it won’t warn you before that happens. It’s good to know that you can visit this restore mode again if you accidentally lose your existing file!
But if what you need to do is bring back a version without replacing your current one, you could just hold down the Option key within this view, and “Restore” will switch to “Restore a Copy.”
Pick that instead, and a new file will open, which you can then save if you wanna. Neat! It’s really nice to know we’ve got some failsafe options around macOS, isn’t it? I could use some more of those in real life, guys.