Duplicate File Scanner Learn more

Compare two folders, find duplicate files in the second folder that already exist in the first, and move them into an organized duplicate directory — preserving folder structure. Everything runs locally in your browser — nothing is uploaded.

Need help cleaning up duplicates? Get human help →

Choose Two Folders to Compare

Select a source folder (original) and a target folder (to check for duplicates)

Ready

📁 Source Folder (X) Original

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📂 Target Folder (Y) Check for duplicates

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Comparison Method

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Content Hash (SHA-256)

Byte-perfect match — most accurate, slower on large files

⚡

Name + Size

Matches by filename and byte size — fast, good for media

🏷️

Name Only

Matches by filename only — fastest, may have false positives

Select both folders to begin

Scanning… 0 files

Reading folder structure…

Scan Summary

Duplicate Types 0

Actions

Duplicate File Scanner

What this helps with

Compare two folders and identify files in the target that already exist in the source
Choose from three comparison methods: SHA-256 content hash, name + size, or name only
Move detected duplicates into an organized _duplicates folder preserving directory structure
Generate a 3-column CSV log: source path, target path, and new duplicate path
Filter and search results by filename, extension, or minimum size

How it works

Select a source folder (X) — this is your reference / original
Select a target folder (Y) — duplicates in this folder will be found
Pick a comparison method and click "Scan for Duplicates"
Review the duplicate report — grouped by matching content
Optionally move duplicates in Y into Y/_duplicates/ preserving their subfolder structure
Export a complete move log as CSV with all three path columns

Example

Source: X/photos/3.txt matches Target: Y/backup/f1/1.txt
After move: Y/_duplicates/backup/f1/1.txt
Log row: X/photos/3.txt → Y/backup/f1/1.txt → Y/_duplicates/backup/f1/1.txt

Privacy

100% local — no data is uploaded or sent anywhere, ever
Works offline after the page loads
File contents are only read for hashing — never stored or transmitted