How to find duplicate photos
Choose the folder with your photos. Each set of copies shows up as a group with the best photo marked Kept. Press Pick all suggested, then Move to Duplicates.
Choose a folder
Press Choose a folder, or drop one on the page; the folders inside it come along. You can also choose a few photos. Hidden folders, such as the thumbnails a phone or a NAS keeps, are left out.
Wait for the groups
Every photo is read in your browser, a few at a time. A JPG with a thumbnail of the right shape is read from that thumbnail, so a folder of thousands takes a minute or two. Stop keeps what was read so far.
Pick what to clear out
Each group keeps one photo, marked Kept. Press Pick all suggested, or tick photos yourself. Press a photo to see it next to the one kept, with the pixels that differ marked.
Move them aside
Move to Duplicates puts the picked photos in a Duplicates folder inside the folder you chose. Or save the list as a CSV file and clear them out in your file manager.
How alike is alike?
Exact copies are found by their size first, then by a SHA-256 fingerprint of the whole file, so only photos that share a size are read in full. For look-alikes, each photo is shrunk to a 32 × 32 grey picture and turned into two 64-bit fingerprints: one from its broad shapes (a DCT hash) and one from its edges (a difference hash). Two photos match when both differ in few bits.
| Level | Finds |
|---|---|
| Exact | Files that are byte for byte the same |
| Very similar | Also resized, re-saved and brightened copies: up to 6 of 64 bits apart in both fingerprints |
| Similar | Also slightly cropped copies and light edits: up to 12 and 10 bits apart. The level to check most carefully |
Groups form around the photo kept, not in chains: every photo in a group matches the kept one directly, so a burst of shots never drifts into one big group of photos that do not look alike end to end. A portrait and a landscape are never matched, and nearly plain pictures, such as a black frame, must match closely.
What happens to your files?
Nothing, until you press Move or Remove. The browser first asks whether this page may change the folder. Moving copies each photo into the Duplicates folder, reads the copy back to check it is byte for byte the same, and only then removes the original. A photo that changed since it was read is left alone.
- Read right in your browser
- One photo always stays in each group
- Moved photos keep their own folders inside Duplicates, so they are easy to put back
- Remove for good asks first and names how many photos and megabytes go
Specs and browser support
| Formats | JPG, PNG, WebP, GIF, BMP and AVIF. HEIC where the browser opens it (Safari); elsewhere a HEIC is matched as an exact copy only |
|---|---|
| Folder size | Built for up to 20,000 photos. Comparing every pair takes seconds; reading the photos takes most of the time |
| Photo kept | Largest dimensions, then largest file, then oldest date taken; among equals, a name without “copy” or “(1)” |
| Limits | Photos over 64 megapixels are matched as exact copies only |
| Browsers | Finding groups and saving the list: any current browser. Moving and removing photos: Chrome and Edge on a computer |
| Price | Free, no account |
Questions
No. The photos are read and compared in your browser, on your device. Nothing is kept once you close the page.
Only when you ask. Move to Duplicates puts the photos you picked in a Duplicates folder inside the folder you chose, where you can look them over. Remove for good asks first, and the photos skip the Recycle Bin.
The one with the largest dimensions, then the largest file, then the oldest date. Press Keep this one under another photo, or in the side-by-side view, to keep that one instead.
Yes. It finds the groups in any current browser, and you can save the list as a CSV file to clear the photos out in your file manager. Moving and removing need Chrome or Edge on a computer.