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Duplicate File Finder

Find byte-identical duplicates among your files in the browser. SHA-256 of every byte, groups listed, CSV report included.

Choose files

0 files ready to compare.

Duplicate groups

Identical files will be grouped by SHA-256 here.

Your file is never sent to a server. It is read and processed by your own browser, and the results are not stored.

How to use it

  1. Choose the files to compare (up to 500).
  2. Scan; identical files are grouped and listed by hash.
  3. Download the CSV report, then clean up in your own file manager.

Limits worth knowing

  • SHA-256 equality is byte identity — two different files with the same bytes are duplicates, by definition.
  • The tool never deletes anything; it reports only.
  • Total batch is capped at 512 MB — the tab must remain responsive.
  • Same hash + same size is the definition; “similar” images require different tooling.

Names lie, bytes do not

A folder from three machines is three naming conventions and one truth: the content. SHA-256 collapses naming noise entirely — “FINAL (2).pdf” and “final-final-new.pdf” turn out to be identical here more often than anyone wants to admit.

Two digests in the report are deliberately left in the output: the point is not trust, it is verification. Compare them anywhere you like.

What a duplicate report should not do

It should not delete, rename or move your files. Anything that removes data off the back of a corner-case match (copied logs, accidental exports) is one click too close to damage. This tool is a report, nothing more.

Frequently asked questions

Does Duplicate File Finder upload my files to any server?

No. Duplicate File Finder runs in your browser, and the file is read there rather than sent to a server for processing. Our host still sees ordinary page-request metadata, which is described on the privacy page.

Is Duplicate File Finder free to use?

Yes, Duplicate File Finder is free, with no paid tier, no account, and no watermark added to your output. The limits are technical rather than commercial: file size, page count and supported formats are listed on this page.

What file formats and sizes are supported?

Duplicate File Finder supports * files up to 512MB directly in your browser.

How does it decide duplicates?

SHA-256 of the full contents, plus the byte size. Two files match only when both match — a name is never part of the verdict.

Is hashing really byte-exact?

Yes — the digest covers every byte. A collision is not something you will ever see in a SHA-256 digest, but this tool reports the digest so you can check it yourself.

Can it read huge files?

Every file is hashed fully, capped at 512 MB total per batch to protect the tab; files above that are reported as skipped rather than silently passed over.

Is anything uploaded?

No. Hashing happens in this tab. There is no server to leak your filenames, hashes or contents to.