Duplicate File Finder

Two files can only be identical if they have exactly the same size, so the tool first groups files by size, which costs nothing. Files with a size of their own are skipped immediately. For the rest, the tool reads every byte and computes a SHA-256 hash, a 64-character fingerprint that changes completely if even a single bit differs. Files with the same size and the same hash are duplicates. The chance of two different files sharing a SHA-256 hash is so small that it has never happened by accident.

Only files with byte-for-byte identical content. The same photo saved again at a different quality, resized, or with edited metadata is a different file, even if it looks the same; finding similar images needs a visual comparison, which this tool does not do. File names, folder locations and dates are ignored, so a renamed copy is still found. Empty files (0 bytes) are all identical to each other and are not counted, because they take no space.

For your safety, browsers do not let web pages delete or move files on your computer. The tool reports what it found: each group lists its files in alphabetical order, with the first marked as the copy to keep and the rest as duplicates in the CSV report. Before deleting, check which copy is in the right folder, and remember that some programs, such as photo libraries and music apps, keep their own copies on purpose. When in doubt, move duplicates to a separate folder first instead of deleting them.

Nothing is uploaded: the browser reads the files directly from your disk. Reading is the slow part, so a folder with many large videos of identical size takes longer than thousands of small files of different sizes. Up to 20,000 files can be compared in one go; for a whole drive, check one folder at a time. A progress bar shows how far the comparison is.