Why Do Duplicate Photos Accumulate on Mac?
Apple Photos and third-party photo editors create additional copies during import. When you AirDrop photos from iPhone to Mac, each transfer creates new files in Downloads — importing these into Photos creates a second copy in the Photos library. Over months of regular use, photo libraries can contain hundreds of duplicate images.
Screenshots and burst photos compound the problem. macOS saves every screenshot as a separate PNG file. Burst mode on iPhone creates 10-30 photos per burst, and importing the entire burst into Photos creates a full copy of each frame.
How Does DupScan Find Duplicate Photos?
DupScan scans all image formats — JPEG, PNG, HEIC, RAW, TIFF, and others — during its regular duplicate scan. No separate photo-specific scan is needed. DupScan's smart filtering lets you focus on image files specifically by selecting the Images category filter.
Grid view is particularly useful for reviewing duplicate photos because it displays file thumbnails side-by-side with KEEP/DELETE badges. You can visually verify each photo before selecting it for deletion.
DupScan currently finds exact duplicate photos — files that are byte-for-byte identical. Similar photo detection (photos that look alike but have different file data) is planned for a future version.
How Can You Prevent Duplicate Photos from Accumulating?
iCloud Photo Library syncs photos automatically between devices without creating duplicate files on each device. Enabling iCloud Photos eliminates the need for manual import via AirDrop or cable, which is the primary source of photo duplication.
Regular scanning with DupScan catches duplicates before they accumulate significantly. Running a quick scan of Downloads, Desktop, and Pictures monthly keeps photo duplication under control. See our complete guide to finding duplicate files on Mac for a full walkthrough of the scanning process.