How do I recover accidental deleted photos on MacBook Air?

If images are deleted from the 'Recently Deleted' folder then they are gone and not recoverable. That said, it would appear that the duplicate feature is quite accurate, and so I doubt that you've lost too much. However, there are two obvious learnings from this: First is to not use the recently deleted folder as a basis for any kind of work such as this sorting you were doing. If you do make an error you have no safety net. Second: This is why a back up is always important.

If Photos crashed after trashing thousands of photo, you may want to try to find out why.

• Typical reasons are a lack of memory or storage. Try to remember, which apps have been running, while you have been working with Photos. Don't run older third-party apps in the background, that might be leaking memory or hogging memory.
• Don't try to mass delete images and videos, if your Mac is low on storage; do it in smaller batches. it is much safer to delete photos only in smaller batches, so Photos will not need so much memory at a time.
• the crash might also have been caused by a data error. If your Photos Library still contains old videos or images in a format, that is no longer supported by macOS 14, trying to open one of them could have caused the crash. In that case yI recommend to remove all incompatible items to prevent further crashes.

It is strange, that the recently Deleted album has been empty, when Photos started up again. This is indicating, that the crash may have left the Photos Library in an inconsistent state and Photos had not yet written all changes back to the Photos Library. Photos is not updating all changes instantly in the library package. Some will only be written when we quit Photos. So the photos you moved to recently Deleted may still be in the library. Watch the Duplicates album, if previously trashed photos will reappear.

Did Photos show a message that it needed to repair the library after it crashed? In that case you may want to check the sidebar with the albums, if there is now a folder or album with "Recovered items" in the name. Items that could not be deleted correctly and are found in the library during a repair may turn up in a "recovered items" album in the sidebar.

If you are not using iCloud Photos, there are two easy ways to make a backup of your Photos Library:

• Time Machine: Back up your photo library on Mac - Apple Support (EG)
• Or a copy of the Photos Library

If you are using iCloud Photos, there is no easy way to make a backup, unless you disable the "Optimize Storage" option, because otherwise any copy of the library will we incomplete. When you are using an optimized iCloud Photos Library, safe the original image files by exporting them.

I accidentally lost some important files before and searched all over my computer but found no backup. So I could only try a data recovery software recommended online. I finally chose Cisdem because it was cheaper than others, lol. And it enables me to pay for the recovery after finding the missing files, otherwise I am afraid of money without getting something back.

Many of us have had poor experience with "data recovery software." Back when we used spinning mechanical drives, deleting files could leave bits of them lying around on the magnetic disk, and such programs could go looking for those, but with solid state drives, it doesn't really work that way, anymore. Some apps may leave some files in caches or other spots, but that's rare. Don't expect much.

Let us know if you have success with that…