Once analysis is complete, Gallery Doctor shows the health of your library and offers three ways to act upon it.

iCloud Photo Library may be great for carrying around a lifetime’s worth of images without taking up all of the available space on iOS devices. But do you really need to carry around every single picture in the palm of your hand?

Pruning bad photos from your library sounds like a great idea, until you realize it’s going to consume hours making decisions about what to keep or discard. Wouldn’t it be nice to have an intelligent virtual assistant to do most of this heavy lifting for you?

The doctor is in

Gallery Doctor (App Store link) promises to be the cure for what ails bloated Camera Roll or iCloud libraries. This inexpensive app analyzes photos, automatically identifies the stuff you probably don’t want, and allows users to review the results prior to purging images from your iPhone. (The app also works on iPad, although it’s not a universal build.)

Gallery Doctor claimed around nine percent of my iCloud Photo Library was “bad,” flagging more than 1,500 images for deletion.

The software uses a combination of machine learning and a so-called Gallery Curation Engine to weed out unwanted pictures, like shots that are blurry, too dark, or generally bad quality. Gallery Doctor also claims to identify “boring” shots, all while performing its magic on the actual device—nothing gets uploaded to the cloud or shared with others.

Of course, what the app considers “boring” could very well turn out to be a user’s precious memories, so Gallery Doctor first performs the analysis, then presents the results in bad and similar categories, along with a third for images it’s less certain about.

Images in the latter category can be acted upon in two different ways: Swiping photos right to keep or left to delete, or tapping red “thumbs down” or green “thumbs up” buttons. For a dozen or two pictures this works well, but reviewing hundreds or thousands of images eventually winds up being not much faster than the manual method, especially if you’re as picky about your library as I am.

If Gallery Doctor doesn’t know what to make of some photos, you’ll have the opportunity to review and keep or delete them.

Bad medicine

Gallery Doctor analyzed more than 17,000 iCloud Photo Library images in about 21 minutes, identifying 1,581 bad, 2,513 similar, and another 1,390 for review, giving me a 34 percent “gallery health” score. Unfortunately, many of the so-called “bad” photos wound up being ultrasound scans of my daughter-to-be, holiday fireworks, or other family events I would never actually delete.

Users can fine-tune Gallery Doctor’s bad photo choices prior to deletion. Everything is selected by default, with a trashcan icon in the lower right corner of each thumbnail; a tap removes the image from removal, or you can tap and hold to see a preview. Sadly, there are no selection shortcuts, so if you only want to delete a handful of images, prepare for serious finger gymnastics from repeated tapping.

Likewise, the “similar” review displays flagged images side-by-side, one as “best photo” and the other with a trashcan icon. While this comes in handy for burst mode shots, in my experience Gallery Doctor identified way too many photos that looked nothing alike.

Gallery Doctor’s poor bedside manner doesn’t do a particularly great job flagging similar photos.

And it gets worse: There’s no option to start over unless you go through all three review stages, at which point Gallery Doctor is supposed to get smarter with subsequent attempts. I wound up having to delete and reinstall the app in order to start fresh—this time with a gallery health score of only 32 percent, at which point I threw up my hands and charged this doctor with malpractice.

Bottom line

Gallery Doctor sounds like a promising solution for scrubbing unwanted photos off your iPhone, but users with larger collections are better off performing this kind of surgery the old-fashioned way instead.