Duplicate File Finder
The Duplicate File Finder scans a large batch of files and compares their actual content precisely via a SHA-256 fingerprint (not just their name or size), to detect files that are byte-for-byte identical regardless of what they're named. The tool shows every duplicate group along with the storage that could be reclaimed, and lets you download only the unique copies bundled into one ZIP archive. All comparing and scanning happens in your browser — no file is ever uploaded to a server.
Files are compared entirely in your browser via a SHA-256 fingerprint — no file is ever uploaded to a server.
Drag files here or choose them
Add as many files as you like to check for duplicates among them
What this tool does
Scans a set of files you choose and identifies which are genuinely identical in content, rather than merely similar in name.
When to use it
- A photo folder containing duplicates under different names.
- Reclaiming storage from repeated files.
- Checking whether a file has other copies before deleting it.
- Merging two folders and wanting to know what they share.
How to use it
- Drag your files onto the drop area or choose them.
- Run the scan and wait.
- Review the groups of identical files.
A practical example
Input
Fifty photos including duplicates saved under different names.
Output
Groups showing which files are identical in content despite their differing names.
Limitations
- The comparison is on content: two files with the same name and different contents are not duplicates, and two with different names and identical contents are — which is the point.
- The same photo saved at a different quality or in a different format is not byte-identical and so does not count as a duplicate.
- This identifies and does not delete; deleting is yours to do on your device.
- Scanning many large files takes time, because each is read in full.
Privacy and processing
The scan happens entirely inside your browser and no file is uploaded to a server.
Technical notes
- Detection compares the files' own contents, which is what makes it entirely reliable: a match means a genuine match rather than a resemblance.
Frequently Asked Questions
The tool computes a SHA-256 fingerprint of each file's content and compares those fingerprints — two files with the same fingerprint are identical in content, even if their names differ.