PDF Tools

Verify PDF Signature

Scans a PDF for signature form fields and produces a plain-text report listing them, along with the page count and document information such as title, author, producer and creation and modification dates. It does not validate certificates or check whether the document was changed after signing.

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Verify PDF digital signature:

Check for digital signature fields
View document metadata
Analyze creation and modification dates
Generate verification report

Note: Full cryptographic signature verification requires Adobe Acrobat or similar software.

How to Use

1Drop one PDF onto the upload area.
2Click the Verify Signature button.
3Download the report; it is a .txt file named after your PDF with -signature-report added.
4Open the report and read the Signature Analysis section, then take any signed document to Adobe Acrobat or similar software for real validation.

About this tool

Updated September 19, 2026

What this actually checks

It looks for signature form fields in the PDF and reports how many it found, along with the document's properties and page count.

The report you download lists each signature field by name, plus the title, author, subject, creator and producer, the creation and modification dates, the page count and the file size. That tells you whether someone has placed a signature field in the document and what the file says about itself. It is a structural inspection, which is genuinely useful when you want to know whether a form is set up for signing at all.

It does not tell you a signature is valid

There is no certificate checking and no tamper detection here. A field being present says nothing about whether it is trustworthy.

Real signature validation means verifying a cryptographic certificate against a trusted authority, confirming it had not expired or been revoked at signing time, and checking that not one byte of the document has changed since. None of that happens on this page, and none of it can be done reliably in a browser. So a report listing a signature field is not evidence that the document is authentic or unaltered. If the answer matters legally or financially, open the file in a reader that performs full validation and shows a signature status, and treat that as the authority.

Reading a result of zero fields

No signature fields found usually means the document was never set up for digital signing, but it does not mean nothing was signed.

A scanned image of a handwritten signature is just a picture on the page, and so is a signature drawn or stamped on with an annotation tool. Neither creates a signature field, so both report zero here while looking perfectly signed to a human. That gap is worth understanding: a document can carry a visible signature and no cryptographic one, which is precisely the situation this report helps you notice.

Where the dates come from

The creation and modification dates are properties stored in the file, and properties can be edited.

They are helpful context and weak evidence. A modification date later than a creation date suggests the file was resaved, which may be entirely innocent. Some documents show Unknown because the fields were never written or were cleared. Treat everything in the report as what the file claims about itself, not as verified fact, and use it to decide whether a document deserves a closer look elsewhere.

Features

Accepts one PDF per run (maxFiles is 1), up to 200 MB.
Counts signature form fields (the AcroForm signature type) and lists their names.
Report includes file name, size in KB, page count, title, author, subject, creator, producer, and creation and modification dates.
Output is always a .txt report, never a modified PDF.
Does not validate certificates, byte ranges or document integrity.
Runs in your browser; the file is not uploaded.

FAQ

Does this tell me whether a signature is valid?

No. It only looks for signature form fields and reports what it finds. It does not check certificates, trust chains, ByteRange coverage or whether the document was modified after signing. The report itself says that full verification needs Adobe Acrobat or similar software.

What does the report contain?

A plain-text file with the file name, size, page count, the document information fields (title, author, subject, creator, producer, created and modified dates), the number of signature fields found and their names.

What if the report says no signatures were found?

That only means no signature form fields were detected. A PDF that has a visible typed or image signature stamped on the page, for example one made with Sign PDF, has no signature field and will show none.

Is my PDF uploaded?

No. The check runs in your browser with pdf-lib and the file is not sent to a server.

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Stamp a typed name on the last page of a PDF at one of six preset positions.

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PDF Metadata Remover

Blank the title, author, subject, keywords, creator and producer fields of a PDF.