External Editors for Photos is an OS X Photos app extension that lets you edit your images on your Mac with any photo editor. To use the tool, locate and double-click an image in your photo library. Hit the edit button found at the upper right of your screen. And then choose the extensions from the bar of icons that appear. Alternatively, you may drag or paste any picture into the image frame. The images edited are immediately saved to your photo library, replacing the original pictures. There is no data loss. And if you didn’t like the edits, you can always recover your original files.