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Free tool

PDF hash generator: get the SHA-256 of any file

Drop a PDF or any other file and get its SHA-256 fingerprint in seconds. The file never leaves your device: the hash is calculated in your browser.

Private by design: nothing is uploaded. The calculation runs on your device.

How to get the hash of a PDF

  1. Drop the PDF into the box above, or choose it from your device.
  2. Copy the 64-character SHA-256 fingerprint that appears.
  3. To check a copy later, paste the original hash in the compare field: if it matches, the file is identical.

What is a file hash?

A hash is a fingerprint of the content of a file: 64 characters calculated with the SHA-256 algorithm, standardised by NIST. The same file always gives the same hash.

Change a single character, an amount or a comma and the hash changes completely. That is why comparing hashes is the reliable way to know whether a PDF has been edited, when the metadata or the appearance prove nothing.

Questions about PDF hashes

Is my file uploaded to a server?
No. The SHA-256 is calculated in your browser with the Web Crypto API. The file never leaves your device and Trampto does not see it.
Does it only work with PDF?
No. It works with any file: PDF, Word, images, ZIP or video. The fingerprint is calculated over the exact bytes of the file.
Why does my hash change if the PDF looks the same?
Because any internal change counts: re-saving, editing metadata or exporting again creates different bytes and therefore a different hash.
Does a hash prove when a document was created?
Not on its own. To prove it existed unchanged since a date, the hash must be recorded by a third party. That is what sealing it with Trampto does.

Turn a hash into proof

Seal your PDF with Trampto: SHA-256 fingerprint, Seal ID and a public link anyone can use to verify it. Your first 3 documents are free.

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