What is Duplicate File Finder?

This duplicate file finder scans your selected files and identifies exact duplicates by computing SHA-256 hashes privately on your device. No files are uploaded. Group duplicates, review them side-by-side, and decide which copies to keep.

SHA-256 catches byte-for-byte duplicates even when filenames or timestamps differ, so a photo copied across three backup folders gets flagged once. Add files in batches, watch the live hash progress, and review the groups before deciding what to keep. Export the full report as CSV for offline cleanup.

How to use

1. Drag and drop files or select a folder of files you want to scan for duplicates.
2. Wait for the tool to compute SHA-256 hashes for each file and group identical files together.
3. Review the duplicate groups, compare file details (name, size, date), and export the report as CSV for cleanup planning.

When to use

• Reclaiming disk space after merging old phone and laptop backups onto one drive.
• Spotting duplicate raw photos from a multi-camera shoot before importing into Lightroom.
• Auditing a shared Dropbox folder where teammates have re-uploaded the same PDFs.

Result

A photographer drops 500 photos from different backup folders. The tool finds 47 exact duplicates across three folders, showing 120MB that can be safely reclaimed without losing any unique photos.

FAQ

Are two files with the same name always duplicates?

No, and that is exactly why this tool hashes the contents. Two photos called IMG_001.jpg from different cameras have different bytes. Two files with totally different names but the same bytes are real duplicates and land in the same group.

Can it scan an entire folder including subfolders?

Yes. Drag a folder into the drop zone and the tool recursively reads every file inside. Hidden system files and macOS .DS_Store clutter all get hashed too, so you can ignore or delete them based on the report.

How big a batch can the tool handle?

Hashing runs file by file, so memory stays low even with thousands of files. The realistic ceiling is total reading time: about 100 MB per second on a modern laptop. Twenty gigabytes of mixed photos finishes in roughly three minutes.

Will it find near-duplicates, like the same photo at two resolutions?

No. SHA-256 is a cryptographic hash: change one pixel and the hash changes completely. The tool only catches identical copies. For visually similar matches you would need perceptual hashing, which is a separate kind of algorithm.

Does the tool delete the duplicates for me?

No, and that is deliberate. It only reports what it finds and lets you export a CSV. Deletion happens on your terms in Finder, Explorer, or the command line, so you stay in charge of which copy from each group survives.

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