PDF signature guide

Electronic signature vs digital signature

Electronic signature is a broad term for electronic actions or marks used to indicate signing or approval intent. A digital signature is a cryptographic mechanism that can use keys and certificates to provide integrity or authentication evidence. The legal effect of either depends on the workflow, evidence and applicable law. PDFandDOC's current Sign PDF feature only adds a visual signature to the page; it does not create a certificate-backed digital signature or e-sign workflow.

What the terms mean

The terms describe different layers of a signing process, so it helps to separate appearance, intent, evidence and cryptography. An electronic signature can be a broad signing action or mark used within an electronic workflow, such as typing a name, drawing a signature or approving a document through a service. A digital signature is a technical mechanism that uses cryptographic signing and verification, commonly with keys and certificates, to provide evidence about document integrity and the signing key. The visible appearance of a signature is not what makes a digital signature cryptographic: a PDF can show a handwritten-looking mark without containing any certificate-backed signature data, and a cryptographically signed PDF can contain validation information that is not obvious from the page image alone. Real signing workflows may also include identity checks, consent records, timestamps, audit events, invitations or organizational controls. Those workflow features are separate from the visual mark itself. PDFandDOC's current Sign PDF feature is deliberately narrower: it places a typed, drawn or uploaded visual signature on the page and flattens that appearance into the output PDF. It does not create certificate-backed signing evidence, verify who signed, or operate a multi-party e-signature service.

PDFandDOC capability boundary

PDFandDOC Visual Sign adds flattened page content only
PDFandDOC does not issue or validate signing certificates
PDFandDOC does not verify signer identity or provide signing invitations, ordering, reminders or audit trails
The current feature is not a certificate-backed digital signature or e-sign workflow
Legal effect and compliance requirements vary by workflow and applicable law; this guide does not provide legal advice
Encrypted/password-protected PDFs are not supported by the current tools

How to choose the right workflow

First identify whether you only need a visible signature mark or whether your workflow requires cryptographic signing evidence.
If a workflow requires certificate-backed signing, identity assurance, audit evidence or jurisdiction-specific compliance, verify those requirements with the provider and applicable rules rather than assuming a visible signature is sufficient.
For PDFandDOC, use Sign PDF only for a visible typed, drawn or uploaded signature placed on PDF pages.
Review the downloaded PDF before sharing it and do not treat the current Visual Sign output as proof of certificate-backed signing.
Ask the recipient or process owner what evidence is actually required before choosing a signing method. A request for a visible signed copy is different from a requirement for certificate validation, identity assurance, timestamps or an auditable signing sequence.
If a digital-signature workflow is required, confirm how signatures are created and validated, which certificate or identity model is used, what happens when the document changes, and which PDF viewer or verification process the recipient relies on.
If only a visible mark is required, still review the final page carefully. Confirm that the signature belongs on the intended document and page, that it does not obscure nearby text, and that the downloaded PDF contains the expected pages before it is distributed.
Keep the unsigned source when the document has continuing operational or legal importance. A retained source makes it easier to distinguish the original content from later visual signing or editing steps and to repeat the workflow if a recipient requests a different format.

Example

Example: imagine a manager receives a PDF approval sheet and is asked only to return a visibly signed copy. The manager can draw a signature in PDFandDOC, position it on the signature line and download the flattened PDF. The page now contains a visible signature mark, but there is no certificate-backed signature object, signer identity validation, cryptographic integrity proof or service-generated audit trail. If the same organization instead requires a certificate that a PDF viewer can validate or an e-sign process with invitation and event records, the visual-signature workflow is not a substitute for that requirement.

The current PDFandDOC Visual Sign workflow is browser-only and local-only: PDF pages, typed signature text, drawn strokes and uploaded signature images are not uploaded to PDFandDOC for the signing operation. Ordinary website requests may still occur, and browser-direct URL intake remains subject to the source site's HTTPS/CORS behavior. Keeping the document operation in the browser does not verify signer identity, create a certificate, establish an audit trail, determine the legal effect of the mark or guarantee that a recipient will accept the result. Those are separate workflow and legal questions.

Questions

What should I check before choosing a signature workflow?

Start with the evidence your recipient or process requires. If the goal is simply to place a visible signature, initials or date on a PDF, a flattened visual mark may be sufficient for that practical task. If the process requires signer identity checks, an audit trail, invitations, consent records, certificate validation, cryptographic integrity evidence or a regulated e-sign platform, use a service designed for those requirements.

Can a PDF show a signature and still have no cryptographic signature?

Yes. A PDF can display handwriting, typed text or a signature image exactly like other visible page content. That appearance alone does not prove who placed it, whether the document changed afterward or whether a certificate validated successfully. Those questions require the signing workflow and the PDF's actual signature data to be examined, not just the visible page.

Does flattening a visual signature create tamper evidence?

No. Flattening makes the placed signature part of the exported page content, which is useful for producing a stable visual result, but it does not create a private-key signature, certificate chain, cryptographic integrity check or independent identity record. If tamper evidence is required, use a workflow that explicitly provides and validates those mechanisms.

Is a visible signature image the same as a digital signature?

No. A visible signature image is page content. A digital signature uses cryptographic signing mechanisms and may use keys or certificates to provide integrity or authentication evidence.

Does PDFandDOC create certificate-backed digital signatures?

No. The current Sign PDF feature creates a visual signature overlay that is flattened into the PDF page content.

Is a visual signature legally binding?

This guide does not make a legal-validity determination. Legal effect can depend on the workflow, evidence and applicable law, so requirements should be checked for the specific use case.

Evidence used for this guide

Reviewed by PDFandDOC product review. Last reviewed 2026-09-19.