Is PDF Verified legally binding?

Yes. PDF Verified signatures comply with the US ESIGN Act, UETA, EU eIDAS regulation, and equivalent eSignature laws in 190+ countries. Every signed document includes a cryptographic SHA-256 fingerprint and a complete audit trail with timestamps and signer hash chain — admissible in court.

How is PDF Verified different from DocuSign?

PDF Verified offers unlimited documents on the $15 Business plan with REST API included. DocuSign charges $40+/user for Business and gates the API behind a $720/month add-on. PDF Verified also includes unique features: public QR verification page on every signed PDF, eStamp designer, AI field auto-detection, and mobile-first signing without requiring an app.

Can I use PDF Verified without a subscription?

Yes. The pay-as-you-go option lets you sign or send one document or envelope for $1.50 without a monthly subscription. Monthly paid plans include a 7-day free trial.

Which file types can I sign with PDF Verified?

Upload PDF, DOCX, TXT, PNG or JPG files. Non-PDF formats are automatically converted to PDF on upload so signers always receive a clean signing-ready document.

How do recipients verify a signed document is authentic?

Every signed PDF includes a QR code on every page. Anyone — even without a PDF Verified account — can scan it to land on a public verification page showing the document status, completion date, SHA-256 fingerprint, and tamper-evidence proof.

Does PDF Verified work on mobile?

Yes — PDF Verified is mobile-first by design. The signing portal uses a native bottom-sheet pattern with touch-optimized canvas signing, sticky CTAs in the thumb zone, and 44px+ touch targets following Apple Human Interface Guidelines. No app download required.

Can I add a company stamp or seal to a document?

Yes. PDF Verified includes a stamp designer for company seals, official seals, approval stamps (APPROVED, PAID, RECEIVED), date stamps, and certified-true-copy marks. Place a stamp on any document like a signature field. On Business plans, the verified stamp library adds auto-incrementing serial numbers, locked metadata, workspace sharing, revocation, and a public QR verification link for every stamp applied.

How do I verify a stamp is genuine?

Each stamp PDF Verified applies mints a unique verification token at /verify-stamp/:token. Scan the stamp's QR code or open the link from the document's audit certificate to see the stamp's name, serial number, the document it was applied to, and whether it has been revoked — so anyone can confirm a company seal or approval stamp is authentic and current.

How do I verify a signature on a PDF is real?

Open the verification page at pdfverified.com/verify and scan the QR code on the signed PDF, paste the verification code, or upload the file. PDF Verified recomputes the document's SHA-256 fingerprint and compares it against the sealed value — if a single byte changed since signing, verification fails. You also see every signer, their timestamps, and the full tamper-evident audit trail. No account is required to verify.

How do I add a digital stamp to a PDF online?

Upload your PDF, open the editor, add a Stamp field, and pick a stamp from your library — a company seal, an APPROVED or PAID approval stamp, a date stamp, or a certified-true-copy mark. The stamp is baked into the sealed PDF with an optional auto-incrementing serial number and a QR code that links to its public verification page. No printer, ink pad, or scanner needed.

What is Digital Signature?

A cryptographic signature using public-key infrastructure (PKI) that mathematically proves authorship and detects any tampering.

A digital signature uses asymmetric cryptography — typically RSA or ECDSA — to bind a private key to a document. Anyone with the matching public key can verify (a) the signer's identity and (b) that the document hasn't changed since signing. Digital signatures are a subset of electronic signatures, distinguished by their cryptographic backing. Under eIDAS they're the basis of Advanced (AdES) and Qualified (QES) electronic signatures. PDF Verified hashes every signed document with SHA-256 and exposes the hash on a public verification URL so anyone can confirm authenticity.

PKI and certificate authorities

Digital signatures rely on a Public Key Infrastructure (PKI): a trusted Certificate Authority (CA) issues a signing certificate after verifying the holder's identity. The signer's software uses the certificate's private key to encrypt a hash of the document; verifiers use the public key to decrypt and compare.

Hashes and tamper-evidence

Before signing, the document is hashed with SHA-256 (or stronger). Any change to a single byte produces a completely different hash, so a digital signature is also a tamper seal — if even one character changes after signing, verification fails.

When you need a true digital signature vs an eSignature

For most commercial contracts a captured eSignature is sufficient. For QES-grade transactions in regulated EU/UK contexts, or for cross-border filings that require non-repudiation, a TSP-issued digital signature is required. PDF Verified offers TSP integration on Business Plus.