Check a signed document.
Drop in a PDF that was signed through Pixasign, or choose one from your device. It is checked against Pixasign’s own record of what was sealed, and you get one of three plain answers: unchanged, changed since it was sealed, or not sealed by Pixasign. No account, and the file is not stored: it is checked and discarded.
Made for the person on the other side of the deal: a quantity surveyor, a landlord, a solicitor, a customer holding a quote. You should not have to take the sender’s word for it.
Haven’t got one? Download a real sealed document and drop it in. It is a sample quotation from a fictional company, sealed by Pixasign on 28 Sep 2026, and it comes back Sealed by Pixasign and unchanged. Nobody signed it: the signature on it was made for the sample, which is a fair reminder that a sealed answer says nothing about who signed.
- The answer
- One of three, in plain words. Never a score, never a maybe.
- How a file is recognised
- Its fingerprint is looked up in Pixasign’s record of what was sealed, not taken on the seal’s word.
- The time
- Every sealed document carries a timestamp from DigiCert, an independent company. Nobody can backdate the seal.
- Your file
- Checked and discarded. Nothing is stored, and no account is needed.
The same check for everyone. You do not need to be a customer, and the sender does not need to stay one.
The three answers, and what each one means.
Not sealed by Pixasign is a different answer from sealed and then changed. An unsigned PDF, a scan, or a document signed with another tool all get the third answer, calmly. It is not a fault: the page is telling you exactly what it can vouch for, and what it cannot. Where a file carries signatures from other tools, the answer names them and says Pixasign does not check those.
Sealed by Pixasign and unchanged
Sealed by Pixasign on 29 Sep 2026
Quotation-QU-2026-0142-
This is the exact file Pixasign sealed, and nothing in it has changed since. DigiCert time-stamped the seal at the time shown below. It does not prove who the signers really are, or that they had authority to sign: each one is identified only by the email address their signing link was sent to.
- Sealed by Pixasign, not an imitationPass
- Unchanged since it was sealedPass
- Covers the whole filePass
- Time-stamped by DigiCert, 29 Sep 2026, 14:32:08 UK timePass
Technical details
Document timestamp, intact, trusted
Sealed by Pixasign but changed since
Do not rely on this document
Quotation-QU-2026-0142-
It was sealed by Pixasign, but something in the file changed after it was sealed. Ask the sender for a fresh copy.
- Unchanged since it was sealedFail
- Covers the whole filePass
Technical details
Document timestamp, invalid
Not sealed by Pixasign
Pixasign did not seal this file
Invoice-2026-0871.pdf
That does not make it a forgery. It may have been signed or time-stamped somewhere else, or not signed at all.
Technical details
NOT SEALED BY PIXASIGN (No Pixasign seal on this document. It carries no signatures at all.)
The three file names, the fingerprint and the certificate reference below are made up for these worked examples. The answers, the headlines, the check lines and the technical details are the checker’s own words.
What is checked, and how a file is recognised.
Four things, in this order. The first depends on Pixasign’s records, not on the file alone, because a seal by itself proves less than it looks.
Sealed by Pixasign, not an imitation
The file’s fingerprint is looked up in Pixasign’s record of what was sealed. A seal that merely carries our name, with no record behind it, is not ours.
Unchanged since it was sealed
The file is compared exactly with what was sealed. One changed character and this fails.
Covers the whole file
A PDF can be signed and then have pages added after. The seal has to cover every byte of the file, or this fails.
Time-stamped by DigiCert
The time inside the seal comes from DigiCert, an independent timestamp authority, applied at the moment of sealing. It is not ours to change, and nobody can backdate it.
Recognised by our records, not by the seal’s say-so.
A seal on its own is not the proof. A timestamp can be obtained by anyone and a field can be given any name, so the file cannot vouch for itself.
What proves a file is ours is that Pixasign holds a record of sealing exactly those bytes. The checker takes the file’s fingerprint and looks for it in that record. Found, and the file is ours and unchanged. Our seal on a file whose fingerprint no longer matches means something changed after sealing. Neither, and Pixasign did not seal it.
- Fingerprint
- SHA-256 bd1687aac8029b28172759e7b1567f4edc0a1ecb100a385a15d687b2d823126b
- Record
- Certificate PXS-BD1687AAC802, sealed 29 Sep 2026, 14:32:00 UK time
- Time
- DigiCert, 29 Sep 2026, 14:32:08 UK time
Want your own paperwork to check out like this?
Every document sent through Pixasign comes back sealed, time-stamped by DigiCert and with an evidence certificate, on every plan, including the free one.
- Free
- 1 user, 3 documents a month, no card
- Paid
- From £19 a month inc VAT, no charge per user
- Your customers
- Never pay, never sign up
- Every document
- Sealed, time-stamped, evidenced
- Checking
- Free for anyone, here, no account needed