DupShelf

Private by design. No upload required.

DupShelf: find duplicate photos without sending them anywhere

Scan a folder on your machine, review exact duplicate groups, choose what to keep, and move extras to dupshelf-duplicate-images or export a CSV. Free. No account. No cloud upload.

Useful when backups, exports, and downloads pile up the same shots under different names.

Start scanningSee how it works

Fast enough for real folders

Progress updates while we hash files. Cancel anytime if you picked the wrong directory.

Stays on your device

Processing happens in the browser tab you opened. Your library never leaves your computer.

You stay in control

Mark one keeper per group, export a CSV, and delete or move files on your own schedule.

How it works

From folder to a reviewed duplicate list in three steps. The entire flow runs locally in your browser.

  1. 1

    Add your images

    Choose a folder on your computer in Chrome or Edge, pick files manually, or drop images onto the page. Paste from the clipboard works too.

  2. 2

    Run a local scan

    We read each file on your device and compare content with a secure hash. Renamed copies and re-exports still show up in the same group.

  3. 3

    Pick keepers, move or export

    Select one file to keep in each group, then move extras into dupshelf-duplicate-images or export a CSV to review in Finder or Explorer before you delete anything.

What you get

A focused tool for exact duplicates, not a bloated cleanup suite.

  • Exact duplicate detection

    Groups files with identical bytes, even when the name, folder, or format differs.

  • Whole-folder scanning

    Point at a library once instead of adding images file by file.

  • Built for large folders

    Handles hundreds or thousands of images on desktop with live progress and a cancel button.

  • Move or export before you delete

    Move duplicates into a dedicated folder or download a CSV. DupShelf never deletes files inside the app.

Use cases

Practical ways people use a local duplicate finder before deleting or archiving photos.

  • Clean up a messy Downloads folder

    Screenshots, memes, and attachments often download multiple times with different names. Scan Downloads, mark keepers, and reclaim space without uploading anything.

  • Prepare photo archives before backup

    Before copying a library to an external drive or NAS, remove exact duplicates so backups stay smaller and restores stay simple.

  • Organize client delivery folders

    Photographers and videographers can verify that exports and selects folders do not contain accidental duplicate deliveries.

  • Deduplicate design asset libraries

    UI kits, icons, and mockups accumulate across projects. Find identical assets even when they live in different project folders.

  • Audit cloud sync duplicates

    Sync tools sometimes create copy-of-copy files after conflicts. A local scan catches byte-identical files sync software may not flag.

  • Free space on a laptop SSD

    When storage is full, exact duplicates are the safest first pass: you only remove files that are provably identical to another.

  • WhatsApp and Downloads clutter (India)

    Forwarded photos and status saves often land in Downloads with new names. Scan once, move duplicates to dupshelf-duplicate-images, and free space without uploading your gallery.

  • Wedding and festival photo bursts

    Multiple guests share the same shots in different chats. DupShelf groups byte-identical copies before you back up to a drive or Google Photos.

Why scan duplicates locally?

Uploading thousands of photos to a website is slow, costly, and hard to trust. A browser-based scan reads files from your disk and hashes them where they already live.

You keep control: nothing is deleted inside the app, and you export a list to review before moving or removing files. That makes exact duplicates the safest first cleanup pass.

Who this is for

Anyone with a growing photo folder and a preference to keep files local.

  • Photographers

    Sort delivery exports, archive folders, and backup drives before you move them to cold storage.

  • Designers

    Deduplicate asset packs, mockup folders, and repeated version saves from clients.

  • Anyone cleaning storage

    Free space on a laptop or external drive without uploading your library to a third party.

  • Creators

    Tame burst shots, edits, and downloads that landed in multiple folders under different names.

Browser tips

  • Chrome or Edge (desktop): use Choose folder to scan an entire directory, including nested folders.
  • Safari or Firefox: add files with Choose images, drag and drop, or paste from the clipboard.
  • Small sample: imageduplicate-test-photos in Downloads (about 11 files).
  • Large stress test: run npm run setup:stress-test, then scan imageduplicate-stress-test-photos (4,500+ real photos).

Exact duplicates vs similar photos

This release finds exact duplicates: files with identical content. That includes true copies, re-saved JPEGs, and the same image saved as both PNG and JPG.

Resized crops and edited lookalikes are not included yet. When similar-image detection ships, it will be optional and clearly labeled. Until then, what we report is limited to byte-for-byte matches.

Guides by topic

Intent-based pages for common duplicate-photo searches. Each guide links to the same private DupShelf workbench.

Questions

Straight answers about privacy, limits, and what the tool does today.

Are my photos uploaded to your servers?
No. Scanning runs entirely in your browser tab. Your files are read from disk on your computer and are never sent to us or stored in the cloud.
How does duplicate detection work?
We hash each file with SHA-256 and compare the result. If two files produce the same hash, their content is identical, even when filenames or folders differ.
Will it find resized, cropped, or edited lookalikes?
Not in this version. We only report exact byte-for-byte matches today. Similar-image detection is planned as an optional mode later.
Which browser works best?
Chrome or Edge on desktop supports folder picking for whole libraries. Safari and Firefox can add multiple files via drag and drop or file picker.
Does the tool delete duplicate files?
No. You choose one keeper per group, export a CSV, and remove or move files yourself in Finder, Explorer, or your preferred app.
How many images can I scan?
Many users scan thousands of files. Very large folders depend on available RAM and CPU. Start with a subfolder if you are unsure, then scan the rest.
Why do duplicates have different filenames?
Copies often get renamed by backups, exports, messengers, or cloud sync. We match content, not names, so those files still appear in the same group.
Is this free? Do I need an account?
Yes, it is free to use in the browser. There is no sign-up and no subscription for the duplicate finder.
What file types are supported?
Common image formats such as JPEG, PNG, WebP, GIF, and BMP. Files must be readable as images by your browser.
Can I use this on my phone?
The workbench is built for desktop browsers with large folders. Mobile can add a few files manually but folder scan is limited.
What is in the exported CSV?
A list of duplicate files with paths, sizes, and which file you marked as keeper in each group. Use it as a checklist before cleanup.
Can I move duplicates into a folder automatically?
Yes, after a folder scan in Chrome or Edge. Non-keeper files can be moved into a "dupshelf-duplicate-images" subfolder inside your library, grouped by duplicate set. Keepers stay where they are.
How is this different from cloud duplicate cleaners?
Cloud tools upload your library. We process locally, which is faster to trust for private photos and avoids upload quotas.

Ready to review your duplicates?

Open the workbench, pick a folder, and walk through each duplicate group at your own pace. Your files stay on your machine the whole time.

Open DupShelf