PDF Digital Signature Verifier Online for Free
Check a PDF's digital signature — no upload, no signup, up to 100 MB.
Your file never leaves your deviceDrag & drop your PDF here
or Max 100 MB · Free · Processed entirely in your browserHow to Verify a PDF's Digital Signature
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Upload your PDF Drag & drop or browse your PDF.
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Confirm No settings needed — every check runs automatically.
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Review the results See signer, time, format, and after-signing changes, right in your browser.
Know what the signature really says
- Private by designYour PDF is processed on your device and never uploaded.
- InstantNo upload queue — your browser does the work locally.
- Free, no signupNo account, no credit card, no trial that expires.
- Byte-level integrity readWe read the signature's own byte range to see if anything changed after signing.
- Plain-language resultsKnow what the signature says, not just pass or fail.
Frequently Asked Questions
Is it free?
Yes. No signup required.
Is my file safe?
Yes — your PDF is processed entirely in your browser and never uploaded.
What does this check?
Whether the PDF has a digital signature, who signed it and when, the signature's format, its change permissions, and whether anything was added after signing.
Does this prove the signature is valid?
No. This is a structural check: it reads what the signature itself records and whether the file changed after signing. It can't validate the cryptographic chain of trust — certificate issuer, revocation, or trust anchors. For legal-grade validation, open the signature panel in Adobe Acrobat Reader.
What's the difference between this and the Sign PDF tool?
Sign PDF adds a visual signature — a picture of your handwritten signature placed on the page. It looks official but proves nothing. A digital signature is cryptographic: it's baked into the file and can show whether the document changed after signing. This tool checks for the digital kind.
Why does it say the document changed after signing?
Bytes were appended after the signature was applied — possibly another signature, filled form data, or an annotation, but possibly an edit. Each signature only vouches for the document exactly as it was when signed.
Max file size?
100 MB.