Photos "duplicates" -- identical videos with different file size, "merging" keeps the smaller file

The larger file size does not necessarily mean the video has the better resolution.

Have you compared the codecs of the videos to be merged, also the pixel size and frame rate? You can see these details in the Info. If the codec of the kept duplicate is HEVC and of the deleted video H.264, but the dimensions in pixels and the frame rate are the same, the HEVC version will give you the same quality as the H.264, but use less storage, because of the better compression.

I found an answer! Appstore, Duplicate Photo Fixer Pro. It has this dialog box...

First it scans your library - took hours for me. Then, it finds the dupes. It allows you to select the criteria that make sense, including preferring larger files to small, or files with metadata to those without, and it "marks" those photos for deletion. You then swallow hard, close your eyes, and press "Trash Marked."

I do not disagree with your helpful assessment. File size does not necessarily equal file quality. So, if I had less than a hundred images, or infinite time, your "just examine each one" method is definitely the way I would choose. However, I have 8,000 dupes. To handle this volume in a reasonable time, I need a power tool with a greater degree of control and automation than Apple provides in Photos. Hopefully this "Duplicate Photos Fixer Pro" will be the proper tool for this job. I will post after to let you know.

If there is silence, it worked. But I will definitely be back to admit I was wrong if it trashes decades of memories. So, I am placing my bets on this ten dollar program to both clean house and keep all the memories intact. Wish me luck!

So, it worked, and it worked well. Léonie is correct that size isn't everything! In my case, preferring the larger size was not always the right thing. The slightly smaller file would have the correct DATE, which was important to me. In the end, I scrolled through all my images to correct any default choices that were wrong, and there were plenty.

I highly recommend "Duplicate Photos Fixer Pro." It lets you decide in an automated way, and then correct any errors. It does not delete anything, but builds an Album of the ones you marked for deletion, so you can do a final review in Photos. It's a capable assistant if you have 1000's of duplicates.

It groups your duplicates, and then you go through and check by hand. In this case you can see that the chosen, green image, has others that are larger, but with the improper date. I made the choice to prioritize date over size, so that the images would stay organized by date.

Once you swallow hard and click "trash duplicates" it does not actually do that, it opens Photos, and creates an Album of the duplicates - a final safety precaution.

Then you go to that album, check it if you have the patience, select All photos in the "Duplicate Marked Photos," swallow hard, right click, and choose "Delete 5,577 items"... or whatever the number is in your case.

You get your space back. I'm not sure how this works with the Cloud, but I will update if there are issues.

All in all, I had good luck buying this app, using it to give provide a bit more control than Apple Photos, and did the actual delete in Apple's Photos. Worked for me. Your mileage may vary.

Hello adk97,

Thanks for that info and for choosing the Apple Support Communities. If we understand correctly, you are having an issue with the behavior of the Photos app when working with duplicates on your Mac. First, try running First Aid on your hard drive with the built in Disk Utility tool, as this can correct simple issues like you're experiencing.

How to repair a Mac disk with Disk Utility - Apple Support

Next, use safe mode to start up your Mac as it does the following things:

• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions
• Prevents Startup Items and Login Items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files

Log in to your user account and test the issue while in safe mode and then restart normally and test the issue again.

Use safe mode on your Mac - Apple Support

Cheers!

Added: It is not compulsory to merge using the "Merge" button. I am always comparing the suggested duplicates and decide, if I want to keep them or which version to keep.

Most items presented as duplicates are either duplicates I created intentionally, because I need two versions of the same image in a slideshow or where I need two different versions of the same image. The other presented duplicates are mostly similar photos, taken in quick succession at the same location. Then I want to be the judge, which image is the best one to keep.

I appreciate the answer, but it does not apply to the question. I have the same issue as akd97. This has nothing to do with safe mode.

When you merge "duplicate" images in the photo app, the larger (and perhaps more data-rich) image is deleted. The concern here is that "merge" keeps a low-res, low-data image and deletes the data-rich original. In other words, maybe the smaller one is a preview of some kind, where the larger retains camera-raw or something, and merging loses that data.

adk97 is saying that...

1) in photos app

2) under duplicates in the sidebar

3) each duplicate will have a twin that is small (in KB) and a twin that is large (in MB)

4) To resolve duplicates, there is a link to Merge 2 items above the twins

5) When clicked, Merge 2 items always deletes the larger one

Two questions:

1) is adk97 (and any user) losing valuable image data when merge makes the choice to delete the larger one?

2) can Merge be set differently to keep the data-rich larger image?