Verify PDF digital signatures: one, several or a whole folder
Drop your PDFs or a folder and see at once whether their signatures are valid and whether the document was touched after signing. Your documents never leave your computer.
Drop your PDFs or a folder here
The tool checks that the signature is intact and which certificate it belongs to. It does not check whether the issuer is trusted or whether the certificate has been revoked: for that, use Adobe Acrobat or an official validator (for example, VALIDe in Spain).
How to check whether a PDF signature is valid
1. Add your PDFs
Drop one or several PDFs, or a whole folder with its subfolders. They are read in your browser and never uploaded to any server.
2. They are checked at once
For each signature, the document’s digest is calculated and checked against the signer’s certificate, and the tool looks for changes made after signing.
3. Review the result
You will see which documents have valid signatures, which were changed or are not valid, and which are unsigned. Click a document to see the details of each signature and download the CSV report.
Why verify signatures with JapalTools
Your documents are not uploaded
Everything happens in your browser: the PDF, the signature and the certificate are not sent to any server.
From one to hundreds of PDFs
Check a whole folder with its subfolders and get a result per document and per signature.
Detects later changes
It tells apart an intact signature, a document modified after signing and a damaged or tampered signature.
Nothing to install, no sign-up
Free, no accounts, on any computer with a current browser.
Frequently asked questions
That the signed content has not changed since it was signed and that the signature matches the certificate included in it. On its own it does not guarantee that the signer is who they claim to be: that depends on whether you trust the certificate’s issuer.
The signature is still intact, but the file has data added after it (for example, a comment, a filled-in field or an edit) that no signature covers. It may be harmless or not: compare it with the original version.
No. A web page has no access to your system’s list of trusted certificates and does not query revocation services. The tool checks integrity, the included certificate, its validity period and the chain carried in the PDF; to decide whether the issuer is trusted, use Adobe Acrobat or an official validator such as VALIDe.
Standard PDF digital signatures (CMS/PKCS#7 and CAdES, also called PAdES), with RSA or elliptic-curve keys, and document timestamps. Signatures using obsolete or non-standard algorithms show as “Cannot be verified”.
Yes: they are standard signatures. Their integrity and certificate are checked although, as in every other case, trust in the issuer is decided by your PDF reader or an official validator.
An image or a visible stamp is not a digital signature and cannot be verified: the PDF shows as “Not signed” unless it also carries a digital signature.
No. The document is processed in your own browser and is not sent to JapalTools or anyone else. When you close the page, no copy remains outside your device.