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Image Tools / Local studio

Image Duplicate Finder

Find repeated image files before you archive, share or hand over a folder. Compare file fingerprints locally and download a JSON report without deleting anything.

Runs locallyNo image upload to Nirmion

Step 1 / Source

Choose one image

JPEG · PNG · WebP · 20 MB

Drop your images here

Or browse for two to 20 authorised JPEG, PNG, or WebP images in output order.

Up to 20 files · 20 MB each · browser processed

Step 2 / Output

Image Duplicate Finder settings

Choose 2 to 20 JPEG, PNG or WebP files, at most 20 MB each and 100 MB combined. No sensitivity slider is needed: the comparison uses complete file bytes.

Prepare the duplicate-file JSON reportThe source is not overwritten. Analysis produces a separate duplicate-file JSON report.
Keep this page open until the download begins.
01No server upload

The selected image is decoded and re-encoded inside this browser tab.

02Working copy released

After download, the preview URL, decoded bitmap, canvas, and selected source reference are cleared.

03Your download remains

Nirmion cannot remove the finished file from your device or browser download history.

Workflow guide

Keep the right copy, with evidence

Each complete file is hashed with SHA-256. Matching fingerprints identify byte-identical copies even when their filenames differ. The report lists each filename, byte size, fingerprint and match status. Compare the result with the untouched source before using it downstream.
A

What you need

Choose 2 to 20 authorised JPEG, PNG or WebP files. Each must be no larger than 20 MB; the complete selection must fit within 100 MB. Select at least two files to enable comparison.

B

Social-ready choices

Select logo.png, logo-copy.png and banner.png. If the two logos contain identical bytes and the banner differs, the report shows 3 files, 2 duplicate files, 1 matching group and 1 redundant copy.

C

What you receive

Review and download a separate duplicate-file JSON report; the original file on your device remains unchanged.

Decision guide

What image duplicate finder measures or changes

Each complete file is hashed with SHA-256. Matching fingerprints identify byte-identical copies even when their filenames differ. The report lists each filename, byte size, fingerprint and match status.

This is an exact-file comparison, not a visual similarity search. Resizing, re-encoding or changing metadata can produce a different fingerprint even when two images look alike. Browser-local processing avoids a Nirmion file upload, but it cannot remove copies stored elsewhere.

How browser SHA-256 hashing works

Useful checks for image duplicate finder

  1. Select logo.png, logo-copy.png and banner.png. If the two logos contain identical bytes and the banner differs, the report shows 3 files, 2 duplicate files, 1 matching group and 1 redundant copy.
  2. Review renamed copies of logos, product photos or campaign assets before handing a folder to someone else.
  3. Use the fingerprint and byte-size columns to document which copies matched. Keep the original folder until you have reviewed the report.

Good to know

Important image boundaries

Why might a PNG not become smaller?
PNG is lossless and browsers do not expose a quality control for it. Choose WebP or JPEG when reducing file size matters more than exact lossless pixels.
Are animated images supported?
No. The workspace accepts still JPEG, PNG, and WebP files. Re-encoding an animated source would otherwise keep only one frame.
What does clearing the file mean?
Because processing is local, there is no Nirmion server copy to delete. The tab releases its working references after success; your downloaded output remains on your device.

Questions answered

Frequently asked questions

Does Image Duplicate Finder upload my image?

No. Supported JPEG, PNG, and WebP decoding, pixel inspection, transformation, and export run in your current browser tab. Nirmion does not send the selected image to its API for this workflow. The result is a separate derivative or JSON report, while the original file on your device remains unchanged and should be retained for comparison.

Why do identical-looking images sometimes not match?

This tool compares file bytes, not appearance. A new compression setting, changed metadata, a resize or a different format changes the fingerprint. Two filenames can differ and still match when the bytes are identical. If you need to find similar photos, crops or alternate exports, this exact-duplicate report is not a substitute for visual review.

Does the tool delete duplicates or scan my folders?

No. It reads only the files you explicitly select and produces a downloadable JSON report. It does not scan other folders, overwrite originals or delete matching files. Compare 2 to 20 JPEG, PNG or WebP files, limited to 20 MB each and 100 MB combined. Keep at least one verified copy before removing anything yourself.