Digital Signatures vs. Drawn or Image Signatures: What's the Difference

"Signing a PDF" actually refers to two completely different technologies, and mixing them up can cause real problems in situations that need formal legal standing. Here's the distinction, clearly.

Drawn or image signatures: visual only

A signature drawn with a mouse, trackpad, or touchscreen, or a pre-made signature image inserted onto the page — both are fundamentally just placing a picture that looks like a signature onto a PDF. It visually completes the act of "signing," but technically it's no different from inserting any other image — it carries no identity verification or tamper-evidence capability.

Digital signatures: cryptographically verified

A genuine digital signature relies on public-key cryptography: the signer holds a digital certificate issued by a certificate authority, and the signing process generates an encrypted checksum of the document's content using a private key. Anyone opening the file can then verify both that a specific identity really signed it, and whether the content has been altered since signing. That's why, once a document is digitally signed, any later modification immediately shows the signature status as "invalid" or "document has changed."

Which one to use

• A drawn or image signature is enough for: internal approvals, informal confirmations, a draft-stage sign-off — anywhere you just need a visual marker saying "I've seen/agreed to this."
• A real digital signature is required for: anything needing legal standing, or when a counterparty explicitly requires "certified e-signature" — high-value contracts, formal agreements that may need to serve as evidence. Use a dedicated digital/e-signature service (DocuSign, Adobe Sign, and similar platforms that handle identity verification and encryption) rather than simply pasting in a signature image.

Which one does LocalPDF support?

LocalPDF supports drawn and image signatures — hand-draw with the Draw tool, or insert a signature image with the Image tool, suited to everyday informal signing. If your situation explicitly requires a legally certified digital signature, use a dedicated e-signature platform for that step instead.