How do I view photos on an external drive without downloading them into the Photos library?

To view photos on an external drive without importing them into your Photos library on macOS Sequoia, try using Preview, Quick Look (Spacebar), or the Finder’s Gallery View instead of opening them in the Photos app. These methods let you browse images directly from the drive without adding them to your library.

Everest 🙏

You can open the Photos app, go to Preferences, and uncheck the "Copy items to the Photos library" box which will allow you to view photos on an external drive without importing them into the library.

No it will not. Photos cannot interact with any images that are not imported into the Library. All unchecking that option will do is a:mean the files won't be managed by Photos and b: create a world of complications and pain in the future - especially if the library is on the internal HD and the Masters are stored on another volume.

That is what's called a Referenced Library. In this set up the files are not copied to the library package, but rather left where you have them on import.

But...

In this scenario you can't use the Cloud Photo Library.

Also:

Photos has no tools to manage images stored outside the package. So this is where the pointless chores come in: Everything is more work for you: You move the images from the camera to your preferred storage. Then import them. Deletions? Delete the image in Photos and then go to your storage and root out the deleted image yourself. Anything like moving your store to another disk to a new computer becomes a world of pain because - and this is where the pain really comes in: If the path to the file is broken for any reason you will need to reconnect it manually. Not really a problem if it's one photo. But if it's 10,000 or 100,00, well that's a lot of pain indeed.

My rule of thumb: If you want to use Photos don't use a referenced library, if you want referenced library don't use Photos.

First: "downloading them into the Photos library" is not what happens. Opening a Photos Library that's on an external drive does not require moving pictures to the internal drive. The pictures are not imported into the Photos app itself. The Photos app is just the instructions for how to make pictures from the data stored in the Photos Library. All the data stays in the Photos Library on the external drive.

If we're talking about a Photos Library, then edits, crops, comments, and so on can't be viewed in any way other than using the Photos app. All the changes that may have been made to the pictures in Photos are stored in the Photos database that can only be understood by the Photos app. This also applies to the "Referenced" Library that Yer-Man warned against.

If you really, really, want to extract the Original Unmodified picture files from the Library without any edits, we could help you with that, but it depends on the vintage of the Library. But it would be better to open it in Photos.

Yes, you can simply use the Preview application on your Mac to view photos directly from the external drive without importing them into the Photos library. Just open the Preview app, go to File > Open, then navigate to the external drive and select the photo you want to view.

If you do decide to migrate from that iPhoto library into Photos, some related info:

• Notes on Migrating an iPhoto Library from… - Apple Community

Finder Quick Look can be used to peek at photos, and Finder can be set for viewing large icons too, as alternatives.

Again, this is only possible if the images are not stored in a Photos Library. Unfortunately the screenshot above indicates that they are.

The screenshot suggests that they are in an old Photos Library. Is this the case?