Saving Mac Photos to an External Drive for a PC

There may be a time when you need to save the pictures from Photos on a Mac to a hard drive that is accessible to a Windows or other non-Mac. To be used on another Mac, you can just drag the Photos Library to an APFS formatted external drive. But even with a Mac, you may want to back up your Library with universally readable jpgs, and in that case the best plan is to Export jpgs. An important consideration ifor saving to either platform is that a Mac's Optimize Storage means that the pictures aren't actually on the Mac.

The major concerns are

1. You can't use a Photos Library directly with a PC.
2. If you want the drive to work with PCs, you need to format it with ExFAT.
3. The Photos Library itself won't work on an ExFAT drive, even on a Mac
4. Optimize Storage with iCloud Photos means you have to download the pictures from iCloud. Export does that for you.
5. If you Export thousands at a time there may be glitches-- and you won't know where they occurred. Then again, it might work.
6. Videos have their own problems. It's best to export them separately.
7. Be prepared for the Export to take days. That's another reason not to try all of them at once. I exported 400 (edited) pictures in about 3 minutes. I exposed 400 originals in about 45 seconds.

The idea is to use the Mac's Photos app to Export the pictures. This won't require a special Mac formatted drive; you can use any format. The usual format for a new disk drive is ExFAT of some sort, and that is OK. You can't use a priority Windows format like NTFS, though, since that isn't writable on a Mac.

You should not depend on a Flash Drive for this. Those things are incredibly slow and unreliable.

When you open the Photos app on the Mac, you can choose the Library view:

to see all of the pictures.

I would click on the Filter icon and choose Photos.

This will eliminate the Videos, which you can do later. Videos often, I'm afraid, generate incompatibilities that can make things take much longer. It's better to of the videos last.

You have two choices of what to export. I think you should do both. You can save the Unmodified Originals; they're the original files just the way they were taken, with no edits. And you can also separately save the Edited versions with all the metadata, edits, and descriptions that may have been added.

The fastest and easiest to export are the is original files with no edits. You could put them all in a folder called Originals. Start with the newest pictures and choose a few hundred. I wouldn't choose them all! How many are safe to do at a time may depend on the free space available on the Mac, the size of picture files, and the speed of the transfer.

Then in the menu bar at the top you can choose File>Export>Export nn Unmodified Originals. You get this dialog:

The "Moment Name" choice will put pictures in folders so that pictures that are taken about the same time will be together. That seems better than having a pile of unorganized pictures. Clicking Export will bring up a dialog that allows you to navigate to the right folder on your external drive.

I suggest that you not do them all at once, because this could take a while. And if anything interrupts the process, then you have to start over.

For the edited pictures, again filter out the Videos. In the menu bar at the top you can choose File>Export>Export nn Photos to get this dialog:

This shows lots and lots of choices! I think I've picked the most appropriate ones.

Later you can do the same with the Filter set to Videos. Definitely do fewer at a time-- videos can be a trial.