Duplicate Image Finder
Find byte-identical duplicate images with SHA-256 — exact matches only, in your browser.
Duplicate Image Finder is a browser-based image tool on ImgToolsBase. Find byte-identical duplicate images with SHA-256 — exact matches only, in your browser. To use it, upload or drop your image and view the result directly in your browser — no signup and nothing to install.
How this tool works
What it does
Groups byte-identical files using a SHA-256 of their raw bytes and reports duplicate groups.
Limitation
Exact duplicates only — not resized, cropped or visually similar images.
Resilience
Unreadable or oversized files are skipped with a reason; the scan continues.
Privacy
All hashing happens locally with Web Crypto; nothing is uploaded.
Duplicate Image Finder in your browser
Duplicate Image Finder scans the files you select and groups together any that are byte-for-byte identical, using a SHA-256 of each file's raw bytes. It finds exact duplicates only — it will not catch resized, cropped, recompressed or visually similar copies.
Select as many files as you like. Each file is size-checked individually, and any file that cannot be read is listed as skipped while the rest are still compared, so one bad file never aborts the whole scan.
The result lists each duplicate group, the count of unique files and any skipped files. Nothing is uploaded; all hashing happens in your browser.
How to use Duplicate Image Finder
- Select the files you want to check in Duplicate Image Finder — you can pick many at once, or drag them in.
- Click Process to hash every file and group the byte-identical ones.
- Review the duplicate groups, unique count and any skipped files.
- Download the duplicate report as a text file.
Why use Duplicate Image Finder
A SHA-256 of each file finds true byte-identical copies with no false positives.
Each file is checked on its own; an unreadable file is skipped, not fatal.
Duplicate groups, unique count and skipped files are all listed in the report.
All hashing runs in your browser with Web Crypto; nothing is uploaded.
Common uses for Duplicate Image Finder
Find identical re-saved copies cluttering a download or export folder.
Spot byte-identical files before archiving a set of images.
Confirm that a copied file matches the original exactly.
Get a quick count of unique vs duplicate files in a selection.
Frequently asked questions
Does Duplicate Image Finder find visually similar images?
No. It detects byte-identical duplicates only. Resized, cropped, recompressed or re-saved versions of the same photo have different bytes and will not be grouped as duplicates.
How does Duplicate Image Finder decide two files are duplicates?
It computes a SHA-256 of each file's raw bytes; files with the same hash are byte-for-byte identical and are placed in the same duplicate group.
What happens if one file cannot be read by Duplicate Image Finder?
That file is listed as skipped with the reason, and the scan continues. As long as at least one file can be read, you still get a report.
Is there a limit to how many files Duplicate Image Finder can check?
Each file is size-checked against the per-file limit; very large files are skipped rather than read into memory. There is no fixed count limit beyond your device's memory.
Are my files uploaded to find duplicates?
No. Every file is hashed locally with the Web Crypto API on this page; nothing is sent to a server.
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