What is the difference between an electronic seal and a drawn signature?
A drawn signature is an image placed on the page. A seal is computed from the content: change a single byte and it fails. That is what makes tampering detectable.
Seal a PDF
Apply an electronic seal that makes any later change detectable.
An electronic seal proves where a document comes from and that it has not changed since. Unlike a drawn signature it is not an image pasted onto the page: it is computed from the content, and a single altered byte breaks it. The original document is not rewritten — the seal is appended, and every earlier revision stays readable.
Your document travels to our servers in Europe just long enough to receive the seal, then it is deleted. We keep no copy.
What a seal proves, and what it does not
An electronic seal answers two questions, and only two: where this document came from, and whether it has changed since. It does not say who read it, who approves of it, or that a named person is bound by it.
The distinction is not about wording, it is legal. The eIDAS regulation separates the seal, which belongs to an organisation, from the signature, which belongs to a natural person. Where the law requires a qualified signature, a seal does not stand in for one.
What it does replace very well is the drawn signature pasted at the foot of a page. That one is an image: it can be moved, copied onto another document, and it detects no change at all to what it is supposed to endorse.
How tampering becomes detectable
The seal is computed from the content. A fingerprint of the file is taken, then encrypted with a private key that only the service holds. Change one byte — a digit in an amount, a letter in a name — and the fingerprint differs, so the seal no longer matches.
The original document is not rewritten. The seal is appended by incremental update: earlier bytes stay where they are, and a PDF reader can show each successive revision. An edit made after sealing therefore does more than fail verification — it is visible, and it can be placed in time.
Sealing needs that private key, and a private key has no business living in a browser. That is the only reason this tool sends your file to our servers in Europe rather than working on your device as most of the others do.
When a seal is the right tool
A seal earns its place whenever an organisation issues a document and the recipient should be able to check its integrity without phoning to ask whether this is really the right version.
- An invoice or quote sent by email, which a recipient could edit before passing it further on.
- A certificate, payslip or statement issued in bulk, where fraud targets one figure rather than the whole document.
- An archived report or set of minutes that you will need to prove, two years from now, is the one drawn up on the day.
What the recipient sees
The recipient has nothing to install and nothing to know: common PDF readers show the state of the seal on opening, and flag a document that has moved since of their own accord.
Our verification tool returns the same finding, signature by signature, with no account and no sign-up. That is deliberate: refusing to let someone check a document you handed them would make no sense.
Common questions
Does a seal prove who signed?
It proves where the document came from and that it has not moved since. It is an organisation seal, not a person's signature: it does not bind a named individual the way a qualified signature would.
Is the original document rewritten?
No. The seal is appended by incremental update: the original bytes do not move, and every earlier version stays readable.
What happens to my file afterwards?
This tool needs a machine: your file is sent to our servers in Europe, processed, then deleted automatically. We keep no copy and we do not read it.