File Duplicate Detector

File Duplicate Detector finds files with identical content among the files or folder you select. It calculates a SHA-256 checksum for each file on your device, groups files with matching checksums, and shows each file’s name, size, MIME type, checksum and group, along with totals for unique files, duplicate groups, duplicate copies and reclaimable space. It only reads files — it never uploads, changes, renames, moves or deletes them.

Duplicate downloads, photo exports and backups quietly waste disk space and make folders confusing. Comparing names or sizes isn’t reliable, but matching cryptographic checksums proves files are byte-for-byte identical, so you can tidy up with confidence.

1. Drop files onto the upload area, click to choose them, or press Choose a folder.
2. Wait while each file’s SHA-256 checksum is calculated — progress is shown.
3. Review the summary of unique files, duplicate groups and reclaimable space.
4. Filter the table to show only duplicates, unique files or files that couldn’t be read.
5. Copy the report or download it as CSV or TXT.
6. Delete unwanted copies yourself in your file manager.

• SHA-256 checksums calculated in the browser
• Files and whole-folder selection
• Duplicate groups with file counts
• Unique files, duplicate copies and reclaimable space
• Large files hashed in pieces to save memory
• Stop and resume checking
• Optional skipping of files with a unique size
• CSV and TXT reports and copy to clipboard

• Keep the copy that is in the folder you organise and back up.
• Double-check before deleting files in system or application folders.
• Use the unique-size option to speed up checks of very large folders.
• Remember that edited or re-saved files are not exact duplicates.
• Run the check again after moving files to confirm the result.