Settings

1. The document

Drop the PDF here, or choose it The document is hashed and read in browser memory. Sign a PDF that has already been signed with PACT to add a second signature page.

2. The signer

3. Sign

Check a signed file against its certificate

Choose a PDF signed with PACT and the certificate JSON that came with it. The file is hashed here and compared with the hash in the certificate.

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What this is, and what it is not

It is an electronic signature with a proper record. Who signed, in what capacity, what they declared, when by their own clock, and the exact document they were looking at, identified by its SHA-256. That record is printed on the signature page and repeated in the certificate.

It is not a digital signature from a certificate authority. No key pair, no certificate chain, no PKI. Viewers will not show a green tick. It also does not use a trusted timestamp service; the time is the device's.

The certificate is the part that proves anything. A hash printed inside a file cannot vouch for that file, because whoever changes the file can change the hash. The certificate records the hash of the finished signed file, outside it. Each party keeps a copy; either can then show the file is unchanged.

Whether it binds is a legal question. Many jurisdictions accept electronic signatures for most contracts, and some documents are excluded or need witnesses or specific forms. PACT does not claim compliance with any statute. Where it matters, ask a lawyer before relying on it.

No network address is recorded. A browser cannot learn its own public address without asking a server, and this page asks no one. The record stands on the name, the statement, the hashes and the time.

Nothing leaves this tab. The document, the signature and both output files are made in browser memory and downloaded to you.