How to Sign a PDF: Electronic vs Digital Signatures Explained

To sign a PDF, open it in a PDF signing tool, create your signature by drawing or typing it, place it on the signature line, and save a new copy. You can do this free in your browser with our Sign PDF tool, or with built-in apps on Mac, iPhone and iPad.

That kind of signature is called a simple electronic signature, and for most everyday paperwork it is all you need. Some documents call for a stronger, certificate-based “digital signature”. This guide explains the difference, what the law says in general terms, and the steps for each device.

Electronic signature vs digital signature

People use the two terms as if they mean the same thing. They don’t.

	Simple electronic signature	Digital (certificate-based) signature
What it is	An image of your signature, a typed name, or a ticked “I agree” box	Cryptographic data linked to a certificate that identifies you
How you make it	Draw, type or upload it	With signing software and a certificate from a trusted provider
Detects later changes	No	Yes, the signature shows as invalid if the file is altered
Typical uses	Leases, consent forms, school forms, delivery notes, freelance contracts	Government filings, company records, tenders, some financial and legal documents
Cost	Free	Usually paid; sometimes issued free by a government ID scheme

A digital signature is a specific technology. It is one way of making an electronic signature, and in EU law the strongest version is called a qualified electronic signature.

Is an electronic signature legally valid?

In many countries, yes, for most documents. Here is a general overview. It is not legal advice, so check with the organisation that asked for your signature or a lawyer when the stakes are high.

United States. The federal ESIGN Act says a signature, contract or other record “may not be denied legal effect, validity, or enforceability solely because it is in electronic form” (15 U.S.C. 7001). It defines an electronic signature broadly, as an electronic sound, symbol or process adopted with the intent to sign (15 U.S.C. 7006). There are exceptions: wills and testamentary trusts, adoption, divorce and other family law matters, court documents, and certain notices such as utility shut-offs, foreclosure and eviction (15 U.S.C. 7003). Most states also have their own e-signature laws.

European Union. Under the eIDAS Regulation there are three levels: simple, advanced and qualified. An electronic signature can’t be refused as evidence just because it is electronic, but only a qualified electronic signature automatically has the same legal effect as a handwritten one in every member state (European Commission eSignature FAQ). An advanced signature must be uniquely linked to you and must reveal any later change to the document.

United Kingdom. The Electronic Communications Act 2000 makes electronic signatures admissible as evidence of a document’s authenticity and integrity (section 7). Some documents, such as deeds that must be witnessed, have extra formalities.

Elsewhere. Many other countries, including India (Information Technology Act, 2000) and Pakistan (Electronic Transactions Ordinance, 2002), have their own e-signature laws, often with a list of documents that still need ink or a certified digital signature.

The practical rule: if a form or portal asks you to sign a PDF and send it back, a simple electronic signature is normally what they expect. If they ask for a “digital signature certificate”, a “qualified signature” or a signature through a particular government service, an image of your signature will not do.

How to sign a PDF online (any device)

1. Open Sign PDF in your browser and choose the PDF.
2. Create your signature: draw it with your mouse, trackpad or finger, or type your name in a handwriting-style font.
3. Tap the page where the signature should go, then move and resize it to sit on the line.
4. Add the date or your initials on other pages if the document asks for them.
5. Download the signed copy and open it to check every page.

The tool works inside your browser, so the document and your signature are not uploaded to a server. For a neater result, write your signature on white paper, photograph it in good light, and use the image if the tool offers that option.

How to sign a PDF on a Mac (Preview)

1. Open the PDF in Preview and click the Show Markup Toolbar button if the toolbar is hidden.
2. Click the Sign button.
3. Create a signature with your Trackpad, with your Mac’s Camera (hold your signature on white paper up to the camera), or on a nearby iPhone or iPad.
4. Click the signature to add it, drag it into place and resize it with the handles.

Apple describes each option in its guide to filling out and signing PDF forms in Preview. Preview remembers your signatures, so next time it is two clicks.

How to sign a PDF on iPhone and iPad

1. Open the PDF in the Files app (save it there first if it arrived by email).
2. Tap the Markup button.
3. Tap the Add (+) button and choose Add Signature.
4. Sign with your finger or Apple Pencil, tap Done, then drag the signature into place and resize it.
5. Tap Done and share the signed file.

Apple’s guide to signing documents on iPhone covers the same steps, including filling in form fields. On iOS 26 and later you can also use the Preview app, which has a form-filling mode with the same Add Signature option.

How to sign a PDF on Windows

Microsoft Edge, the default PDF viewer in Windows 11, has no dedicated signature tool, but its inking tool can be used to sign, according to Microsoft’s Edge PDF reader documentation. Open the PDF in Edge, choose the draw (ink) tool in the PDF toolbar, sign with your mouse, pen or touchscreen, and save.

A mouse-drawn signature often looks shaky. A browser signing tool usually gives a cleaner result because you can draw your signature once, larger, and then scale it down onto the line.

How to sign a PDF on Android

The Google Drive app can fill in PDF forms (open the PDF, then Edit > Form Filling), as described in Google’s help page. For a signature, the simplest free route is a browser tool:

1. Open Sign PDF in Chrome and choose the PDF from Downloads or Google Drive.
2. Draw your signature with your finger. Turn the phone sideways for more room.
3. Place it, download the signed copy, and share it from your Downloads folder.

Tips for a signature that gets accepted

• Sign every place the document asks. Look for initials boxes on each page and a date line next to the signature.
• Keep it in proportion. A signature should be roughly the height of two lines of text, not spread across half the page.
• Don’t edit the document after signing. Any change after signing can raise questions about which version you agreed to.
• Send the full document. If you need to add supporting pages, combine them with Merge PDF, and see how to compress a PDF if the result is too big to email.
• Keep a copy. Save the signed PDF with a clear name, such as lease-signed-2026-10-21.pdf.

FAQ

Is a drawn signature on a PDF legally binding?

In the US, the EU, the UK and many other places, an electronic signature is not invalid just because it is electronic, so a drawn signature is usually fine for everyday contracts. Some documents, such as wills, are excluded or need extra formalities.

What is the difference between an electronic and a digital signature?

An electronic signature is any electronic sign of agreement, such as a drawn or typed name. A digital signature uses a certificate and cryptography to prove who signed and to show if the file was changed afterwards.

Can someone copy my signature from a signed PDF?

An image of a signature can be copied, just like a signature on a scanned paper document. Share signed files only with the people who need them.

Do I need to print, sign and scan instead?

Rarely. Unless the organisation insists on a wet-ink signature, signing electronically is quicker and gives a cleaner file than a scan.