Duplicate File Finder
Find duplicate files in any folder by comparing their contents with SHA-256. See wasted space, choose which copy to keep and export a report. Free and private.
- No upload — 100% private
- Instant, on your device
- Free, no sign-up
- Works offline once loaded
How it works
How to use Duplicate File Finder
Click “Choose folder” (or drag a folder onto the page). Files are read on your device, not uploaded.
Click “Find duplicates”. Same-size files are checked quickly first, then compared by SHA-256 of their full contents.
Review each group and pick which copy to keep — or use Keep oldest, Keep newest or Keep shortest path for all groups.
Export the CSV or TXT report (or copy the duplicate paths) and delete the extra copies in your file manager.
Why use it
Why use our Duplicate File Finder tool
Exact matches by content
Files are grouped by size, then compared with SHA-256 of their contents. Renamed copies are found; different files that share a name are never mixed up.
Fast on big folders
Only files that share an exact size are read, and a quick check of the start and end rules most of them out before a full hash — with a progress bar and Cancel.
Wasted space at a glance
See how many extra copies there are and how much disk space you'd free, group by group and in total.
Smart keep rules
Keep the oldest, the newest or the copy with the shortest path in every group with one choice, then fine-tune any group by hand.
Exportable report
Download a CSV for Excel or Google Sheets, a readable TXT, or copy the list of duplicate paths to the clipboard.
Private
Your photos and documents are never uploaded. Everything is hashed with your browser's built-in Web Crypto.
FAQ
Frequently asked questions
Can this tool delete the duplicates for me?
No — browsers aren't allowed to delete files on your computer, which also means a web page can never damage your folders. Export the report or copy the duplicate paths, then delete those copies in File Explorer, Finder or your file manager.
How does it decide two files are duplicates?
Only identical contents count. Files are first grouped by exact size, then a quick SHA-256 of the first and last 64 KB filters the candidates, and finally the whole file is hashed with SHA-256. Names and dates don't matter.
Does it find similar photos, such as resized or edited copies?
No. It finds exact duplicates only. A resized, re-saved or edited photo has different bytes, so it is treated as a different file. That also means there are no false positives.
How many files can it scan?
Tens of thousands of files work fine on a laptop. Files are read in 4 MB pieces, so even very large videos don't need to fit in memory. Time depends mostly on how much data shares the same sizes.
Are my files uploaded?
No. The folder is read by your browser and hashed on your device. Nothing is sent to a server, and closing the tab discards everything.
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