diffesq.

Compare two images and see what changed

To compare two images, drop them into Diffesq: it compares them perceptually on your device and shows where they differ. There's also a duplicate finder that scans a whole photo folder for images that look the same — by looking, not just hashing.

Compare two images

How it works

  1. Drop an image on each side of the workbench.
  2. Diffesq decodes and compares them locally using perceptual methods.
  3. Review the comparison and where the images diverge.
  4. For whole folders, use the duplicate finder to group visually similar photos.

What image comparison covers

  • Perceptual comparison of two images — differences a byte comparison can't see.
  • Folder scanning for duplicates and near-duplicates, including a neural-embedding "Similar" mode that finds images that merely look alike.
  • All decoding and matching runs on your device; photos are never uploaded. Cleanup (moving or deleting duplicates) needs a browser with folder write access — currently Chrome and Edge.

Free vs Pro

Structured-file comparisons run in full on your device on the free tier, with about a third of the results shown as a preview; Pro unlocks the complete results and clean, unwatermarked exports (HTML, Markdown, JSON, PDF).

See Pricing for plans — $2.97/month, $27.99/year, or $49 once.

Privacy

Every comparison runs locally in your browser. Your files are never uploaded — there is no server that receives them, and the page keeps working with Wi-Fi turned off. Details in the Privacy Policy.

Frequently asked questions

Are my photos uploaded to a server?

No. Images are decoded, hashed, and compared entirely in your browser — the privacy test suite literally fails the build if any request carries file data.

Can it find duplicates that were resized or re-saved?

Yes — perceptual matching catches images whose bytes differ but whose content looks the same, and the Similar mode uses a neural embedding for looser visual matches.

Do I need an account?

No. Comparisons run without any signup. Pro features unlock with a license key — still no account or login.

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