Electronic Signature vs Digital Signature — What's the Difference?

"Electronic signature" and "digital signature" are often used as if they meant the same thing. They do not. One is a legal idea that covers almost any way of signing on a screen; the other is a specific cryptographic technique. Mixing them up leads people to buy certificates they do not need, or to send a simple signed PDF where a certificate-based signature was actually required.

Short answer: an electronic signature is any electronic sign that you agree to a document, such as a drawn or typed signature on a PDF. A digital signature is one particular kind of electronic signature that uses a certificate and cryptography to prove who signed and that the file has not changed since. Every digital signature is an electronic signature; most electronic signatures are not digital signatures.

What is an electronic signature?

An electronic signature (e-signature) is any electronic data you attach to a document to show that you sign it. The EU's eIDAS Regulation defines it in almost exactly those words, and US law (the ESIGN Act and the state UETA laws) is similarly broad: what counts is the intent to sign.

Common forms:

• a signature drawn with a finger, mouse or stylus and placed on a PDF
• your name typed in a handwriting-style font
• a scanned image of your ink signature inserted into a document
• ticking "I agree" or clicking "Accept" in an online form

When you add a signature to a PDF with SigPDF, you create this kind of signature: a visible mark embedded in the page.

What is a digital signature?

A digital signature is a technical mechanism based on public-key cryptography. In outline:

1. A certificate ties a key pair to a person. A certificate authority (CA) or, in the EU, a trust service provider checks the signer's identity and issues a certificate for their public key. The matching private key stays with the signer, often on a smart card, token or in a remote signing service.
2. The document is fingerprinted. Software computes a hash, a short value that changes completely if a single byte of the file changes.
3. The fingerprint is signed with the private key and stored inside the PDF together with the certificate.
4. Anyone can verify it. A PDF reader recomputes the fingerprint and checks it against the signature using the public key in the certificate.

That gives two things a plain e-signature cannot show on its own: who signed (as far as the certificate's identity check goes) and integrity, meaning any later change to the file breaks the signature.

Key differences at a glance

| | Electronic signature | Digital signature | |---|---|---| | What it is | Any electronic sign of agreement | Cryptographic signature backed by a certificate | | What you see | Your signature on the page | Often a signature field plus a validity panel in the reader | | Proves who signed | Only through surrounding evidence (emails, logins, witnesses) | Through the certificate's identity check | | Detects later changes | No | Yes, any change invalidates it | | What you need | A signing tool or app | A certificate and software that can use it | | Typical use | Contracts, forms, offer letters, consent slips | Regulated filings, some public-sector and court processes, qualified signatures in the EU |

Legal weight

United States

The ESIGN Act (15 U.S.C. § 7001) says a signature or contract may not be denied legal effect solely because it is electronic. Section 7003 lists the exceptions, for example wills and testamentary trusts, adoption and divorce matters, court documents and certain notices such as utility shut-offs or the cancellation of health insurance. US law does not generally require a certificate-based digital signature; individual agencies or contracts may.

European Union

eIDAS distinguishes three levels:

1. Simple electronic signature (SES): any electronic data used to sign. It may not be denied legal effect or admissibility as evidence just because it is electronic (Article 25(1)).
2. Advanced electronic signature (AES): uniquely linked to and capable of identifying the signer, created with data under the signer's sole control, and linked to the document so that changes are detectable. In practice this is usually a certificate-based digital signature.
3. Qualified electronic signature (QES): an advanced signature created with a qualified signature creation device and based on a qualified certificate from a qualified trust service provider. Only the QES has the same legal effect as a handwritten signature by law (Article 25(2)).

National law decides when a document needs a particular form. In Germany, for example, where the law requires written form, an electronic replacement needs a QES (§ 126a BGB), and for some documents, such as an employment termination, even that is excluded (§ 623 BGB).

How to tell which kind a PDF has

• Look at the page. A drawn or typed signature is part of the page content. It looks like a signature but carries no certificate.
• Open the signature panel. Readers such as Adobe Acrobat Reader show a signature bar or panel when a PDF contains certificate-based signatures, with a status such as valid, invalid or unknown. Microsoft Edge's built-in PDF reader can also view and validate certificate-based digital signatures.
• Edit and re-check. If a document was digitally signed and someone changes it afterwards, the reader reports that the signature is no longer valid.

Which one do you need?

An electronic signature is enough for most everyday documents: employment and freelance contracts, NDAs, leases, purchase orders, school and medical consent forms, offer letters. What matters is that the other party accepts it and that you can show later who signed, which the email in which you sent the signed PDF usually covers.

A digital (or qualified) signature is needed when a law, an authority or the contract itself requires it, for instance some government portals and regulated filings, court submissions in certain countries, or, in the EU, documents that must meet written form electronically.

If a form simply says "please sign digitally", ask what is meant. In everyday use people often say "digital signature" when any e-signature would do.

How to get a digital signature if you are asked for one

• Use the requester's platform if they sent you a signing link; it takes care of certificates and audit records.
• Get a certificate from a CA or, for a QES in the EU, a qualified trust service provider. Many offer remote signing so you do not need a card reader.
• Sign the PDF with certificate-capable software. LibreOffice, for example, can sign an existing PDF with a certificate installed on your computer via File → Digital Signatures → Sign Existing PDF.

Where SigPDF fits

SigPDF creates electronic signatures: you draw or type your signature, or insert an image of it, place it on the PDF together with initials and a date, and download the signed file. Everything happens in your browser, and the document is not uploaded. SigPDF does not apply certificate-based digital signatures and does not produce an audit trail, so for a document that requires a qualified or certificate signature, use one of the routes above.

Frequently asked questions

Is an electronic signature the same as a digital signature?

No. An electronic signature is the broad category: any electronic way of signing. A digital signature is one specific, certificate-based type within that category.

Is a digital signature more legally binding?

Not automatically. Both can be legally binding. A certificate-based signature gives stronger evidence of who signed and that the file is unchanged, and in the EU only a qualified signature is legally equivalent to handwriting. For most contracts, a simple electronic signature is valid.

Can a drawn signature on a PDF be disputed?

Yes, just as an ink signature can. The PDF itself does not prove who placed the signature, so keep the surrounding evidence: the email exchange, the date you sent the signed file, and any confirmation from the other side.

Can I create a digital signature for free?

Signing software that can use certificates exists for free (LibreOffice is one example), but the certificate is the hard part: it must come from a provider the recipient trusts. Self-made certificates are technically possible, but most recipients will see them as "unknown" or untrusted.

Sources: 15 U.S.C. §§ 7001, 7003; Regulation (EU) No 910/2014 (eIDAS), Articles 3, 25 and 26; BGB §§ 126a, 623; Microsoft Learn, "PDF reader in Microsoft Edge"; LibreOffice Help, "Signing Existing PDF". General information, not legal advice.