Verify a PDF signature online

Based on the ESIGN Act (15 U.S.C. 7001) · Reviewed in October 2026

Drop the original PDF and the signed one. The tool compares the fingerprint of the original with the one on the certificate.

Drop the original PDF and the signed one

Choose file

Your file never leaves your device.

How to verify a signed PDF in four steps

1Drop the original PDF, the one before anybody signed it.
2Drop the signed PDF, the one with the certificate page at the end.
3Wait a second. The tool computes the SHA-256 code of the original on your device.
4Read the result. It says in one line whether the fingerprints match.

What each result means

«The fingerprint matches.» The original did not change since it was signed.
«The fingerprint does not match.» The original you dropped is not the one that was signed. Ask the other party for their copy.

A mismatch is common after someone re-saves the file. Printing to PDF or adding a comment both change the code.

Which signatures it checks

It checks certificates made with the free PDF signer. Those carry the fingerprint of the original on their last page.

Signatures sealed with a digital ID from a certificate authority show their own panel in a desktop PDF reader. Open the file there to see who issued it.

What is a SHA-256 fingerprint?

It is a code of 64 letters and numbers computed from every byte of a file. The same file always gives the same code.

Change one character and the code is completely different. That makes it a reliable way to prove a file stayed the same.

When to verify a signed PDF

Before you pay. Confirm that the signed quote matches the one you approved.
Before a dispute. Prove that the contract you hold is the one both sides signed.
When files go back and forth. Catch an edited copy before it replaces the real one.
At an audit. Show that the records in your folder did not change after signing.

Keep the files that make the check work

Store the original PDF and the signed PDF in the same folder. Give them names that pair up, such as lease-2026.pdf and lease-2026-signed.pdf.

Send the original to the other party along with the signed copy. Then both sides can run the check on their own.

Avoid opening and saving the original in another program. Some readers rewrite the file on save, and the code changes with it.

Nothing gets uploaded

Both files are read inside your browser. The comparison happens on your device and neither file is sent anywhere.

Documents sent from a SignSolú account can also be checked at signsolu.com/verificar by uploading the signed file alone.

Frequently asked questions

Is the signature checker free?

Yes. No account and no limit.

Do I need both files?

Yes. The original gives the fingerprint and the signed file carries the certificate.

Can it verify a certificate-based digital signature?

No. Those are validated by the reader that trusts the certificate authority. This tool checks SignSolú certificates.

Why does the result say it does not match?

The original you dropped differs from the one that was signed. Even a re-save or a new comment changes the code.

Are my files uploaded?

No. Both files stay on your device.