How verification works
1
Drop in the signed PDF
Click Choose a file or drag and drop the signed PDF into the box on the page.
2
Your browser reads the file
The PDF opens right on your own device. Nothing is uploaded anywhere while it is being read.
3
It becomes a fingerprint
The file is reduced to a 64-character fingerprint using SHA-256. Change one letter anywhere in the document and every single character of the fingerprint changes. That is what makes it reliable.
4
The fingerprint is looked up
Only the 64-character fingerprint is sent to Suresign. A match means this is, byte for byte, the exact file that was sealed. The record behind it comes back to your browser.
The three possible results
Deleted documents still verify. If the sender deleted their copy, your copy did not stop being real. The result will note that the sender has since deleted their copy, but the file itself is still genuine.
What a Verified result proves
A Verified result proves three things:- The file you hold is exactly the file that was sealed when signing finished.
- You can see who was asked to sign, and when each person did.
- The history behind the document is unbroken and unedited.
What verification does not prove
No electronic signature, including Suresign, can prove:- Who was actually sitting at the keyboard when they signed. This is true of every e-signature service in the world.
- That a printed or scanned copy is genuine. Only the original PDF matches.
Finding the verify address on the document
The address suresign.si/verify is printed on every page of every sealed PDF, in the strip at the bottom. You do not need to remember it: it is right there on the document itself. The same strip also prints the document identifier, which the checker reads to distinguish “this is our document but somebody changed it” from “we have never seen this file.”Your privacy
Your file never leaves your device. All that is sent to Suresign is the 64-character fingerprint. The full document content stays entirely on your computer.Always keep your own copy of the completed PDF and certificate. Verification works best when you hold the original signed file.
Related pages
Audit trail and certificate
Learn how the unchangeable history and certificate are built.
Legal validity
Understand which laws recognise Suresign signatures.
How signing works
See what signers experience from opening the link to clicking Finish.

