Electronic or digital signature: telling the two apart
"Electronic signature" is the umbrella: any electronic way of showing you agree, from a typed name to a drawn mark on a page. A digital signature is one technique under that umbrella, a cryptographic code tied to a certificate that lets software confirm who signed and whether the file changed afterwards. PDFGym's Sign PDF makes the first kind, never the second.
Two requests on the same Friday
Marek runs the office of a small architecture studio. At 3 pm two emails land. A client wants
the four-page fee_proposal_v3.pdf "signed and sent back today". A public tender
portal wants bid_declaration.pdf uploaded by Tuesday noon, "signed with a
qualified electronic signature of the managing director".
Same verb, different products. The client will open the file, see a signature on the last page and file it. The portal will run software over the upload, look for a certificate from an accredited provider, and reject anything else, however neat the handwriting. Working out which case you are in is most of the job.
A broad category and one technique inside it
Electronic signatures are a family: ticking an "I agree" box, typing your name under an email, clicking through a signing platform, placing a picture of your handwriting on a page. What they share is intent, a person using an electronic method to accept a record.
A digital signature is the member built on public-key cryptography. Your software takes a fingerprint (a hash) of the document and signs it with a private key only you control. A certificate, issued by a provider who checked your identity, carries the matching public key. Any compatible reader can then confirm, without asking you, which certificate signed and that the signed content has not changed by a single byte.
Every digital signature is therefore an electronic one, while most everyday electronic signatures involve no cryptography at all. People blur the words, and "please sign digitally" in an email often just means "don't print it".
Side by side: a mark on the page versus a certificate
| Question | Visible mark (drawn, typed, scanned) | Certificate-based digital signature |
|---|---|---|
| Where it lives | In the page content, like any picture | In a signature field holding cryptographic data, with or without a visible box |
| What links it to you | Context: the email it came in, the sender's account, a platform's records | A certificate issued after an identity check, plus a private key under your control |
| If the file is edited later | Nothing flags the change | A reader reports the signature as invalid or the document as modified |
| Who can check it | A person looking at the page | Any reader with a signatures panel |
| What you need | A browser or PDF reader and your signature | A certificate from a provider, a national eID or your organisation's IT, plus signing software |
How the law frames it, in outline only
This is general background, not legal advice. Whether a given signature is acceptable depends on the country, the type of document and what the parties agreed; the person asking, or a lawyer, decides that.
European Union. The eIDAS Regulation (EU) No 910/2014 has three levels. A plain electronic signature, often called simple, is any electronic data a person uses to sign. An advanced one must be uniquely linked to and able to identify the signer, be created with means under their sole control, and reveal later changes to the data. A qualified one is an advanced signature made with a qualified signature creation device and backed by a qualified certificate. Only that top level carries the legal effect of a handwritten signature across all member states, and the regulation says no signature may be refused legal effect merely for being electronic.
United States. The federal ESIGN Act and the state laws based on UETA give electronic signatures legal effect for most transactions without prescribing a technology. Both exclude some documents, wills being the best-known example, and a counterparty can still insist on a particular method.
What Sign PDF creates, and what it leaves out
Sign PDF draws your signature, initials, date or text straight into the page content as an image: not a movable annotation, not a certificate signature. It does not verify identity, attach a certificate, add a trusted timestamp or keep an audit trail. What it does verify is the output. The new copy is reopened, its pages and selectable text are compared with the original, and each marked page is rendered to confirm the mark shows.
If the file contains certificate signature fields, the tool warns you and waits for you to tick that you want to continue, because writing a new copy of a signed PDF can invalidate a signature someone applied earlier.
When a visible electronic signature is all the request needs:
- Open Sign PDF and choose the file. Password-protected PDFs are not accepted.
- Create your mark with Draw, Type or Upload.
- On the right page, use Place signature, plus Place date or Place initials if asked. Drag each mark onto its line and adjust its size.
- If the signature-field warning appears, ask the sender before ticking it.
- Choose Add marks to PDF and let the checks finish.
- Download the signed copy and keep the unsigned original.
A worked example with placement tips is in putting a handwritten signature on a PDF.
Clues in the request that tell you which one
- Qualified, advanced, QES, certificate, trust service provider, PAdES or "verifiable": certificate signature.
- A validating upload portal, a bank, a court, a notary or a government form: usually certificate-based, often with a list of accepted providers.
- "Sign and return", "initial each page" or a printed signature line: a visible mark is normally what they expect.
- A link to the sender's signing service: sign there, so their records stay complete.
If the request is vague, reply with one line: "Do you need a certificate-based signature, or is a signed copy fine?" That costs less than a rejected upload.
Where people get it wrong, and the fix
- A drawn mark sent where a certificate was required. The recipient's signatures panel shows nothing. Sign again with a certificate; no tool converts a picture into one.
- Editing after certificate signing. Merging, adding pages or compressing the file writes a new file and breaks the signature. Make every change first and sign last.
- Marking up a file someone already certificate-signed. Their signature may then show as invalid. Ask whether they want you to sign in their system instead.
- Reading "valid" as "approved". A valid digital signature shows who signed and that nothing changed, not that the terms are fair or the signer had authority.
When a browser tool is the wrong choice
For a qualified signature, go to a qualified trust service provider, use a national eID card or mobile ID where your country offers one, or ask your employer's IT department. Setting up a certificate signature covers the options.
If the sender uses an e-signing platform, sign through their link. Wills, deeds, court filings and notarised documents have their own formal rules, sometimes witnesses or paper originals, so confirm with the authority or a lawyer first. For everyday paperwork on Mac, Windows and phones, the general signing guide lists the built-in options.
Short answers on signature types
- Does a qualified electronic signature have to be visible on the page?
- No. Its weight sits in the cryptographic data. Many programs add a visible box with the name and time, but an invisible certificate signature can be just as valid.
- Can a drawn signature be upgraded to a digital signature later?
- No. A digital signature is created with a certificate and private key over the final file, so you sign again with the certificate.
- Is my name typed under an email an electronic signature?
- It can be, since these laws look at intent rather than form. Whether it binds you depends on the applicable law and what was agreed, which this page cannot answer.
- What happens when the signing certificate expires?
- The signature does not vanish, but some readers later show it as unverifiable unless a trusted timestamp and validation data were embedded at signing. Long-term signing options exist for that reason.
Related signing pages
- Add signature to PDF Place a visible signature, initials or a date on a PDF without uploading it.
- How to sign a PDF Built-in signing options on each device, and when a drawn mark is acceptable.
- Create a digital signature Where certificates come from and how to sign so a reader can verify it.
- Sign a document Every signing guide, sorted by the job in front of you.