Delete duplicate photos

Photos attempts to avoid importing the exact same photo a second time, but that's as far as it goes in reducing duplication. If you (intentionally or inadvertently) manage to import duplicates, Photos does not provide a mechanism to detect and remove them.

There are third-party applications that can help you detect and deal with duplicate images, for various definitions of "duplicate" (identical image and name, identical image renamed, resized image, similar image, et cetera). If you use one, be sure it works through defined interfaces rather than trying to manipulate the Photos library directly.

If duplicate photos are in series , leave the first photo and hold the shift and key click on rest of duplicate photos to get selected .

Right click on any one of them and click on delete .