How to Sign a PDF (Free, on Any Device)

You can sign a PDF for free without printing it. On a Mac, open the PDF in Preview and use Tools → Annotate → Signature. On any device, use a free online tool like Smallpdf or iLovePDF. Here’s how to sign on every platform, plus how to create a reusable signature.

Which method should you use?

Method 1: Mac Preview (built-in, offline)

1. Open the PDF in Preview (double-click it).
2. Click the markup icon (pencil in a circle) in the toolbar.
3. Click the Signature icon → Create Signature.
4. Sign using your trackpad, your camera (sign on paper and hold it up), or a nearby iPhone or iPad.
5. Click the signature to place it, then drag to position and resize.
6. Save with File → Save.

The signature is stored for reuse — next time, just click it to place it again.

Method 2: Online tools (any device)

Use Smallpdf Sign or iLovePDF Sign:

1. Upload your PDF.
2. Click Sign → create a signature (draw, type, or upload an image).
3. Click where you want it and place it.
4. Download the signed PDF.

For sensitive documents, prefer the offline method (Mac Preview or Adobe Reader) so your file never leaves your device.

Method 3: iPhone and Android

• iPhone: open the PDF in the Files app, tap the Markup (pen) icon, then + → Signature, and place it. Full guide: how to sign a PDF on iPhone.
• Android: use the free Adobe Acrobat Reader app → open the PDF → Fill & Sign → place a signature.

Method 4: Windows without extra software

Windows has no built-in PDF signer, but the free Adobe Acrobat Reader app handles it:

1. Open the PDF in Acrobat Reader.
2. Click Fill & Sign → Sign yourself → Add signature.
3. Draw, type, or import your signature and place it.

Creating a reusable signature

If you sign documents often, create one signature once and reuse it:

• Mac Preview, iPhone Markup, and Acrobat Reader all save your signature for future use.
• For a cleaner look, sign on white paper, photograph it in good light, and save it as a transparent PNG to place in any tool.

Electronic vs. digital signatures

These sound alike but differ:

• Electronic signature — an image of your signature placed on the PDF. Fine for most everyday documents (contracts, forms, permission slips).
• Digital signature — uses cryptography to verify who signed and that the file wasn’t altered. Required for some legal and government documents.

For everyday use, an electronic signature is all you need.

Common problems and fixes

FAQ

How do I sign a PDF for free?

Mac Preview, iPhone Markup, Adobe Acrobat Reader, and the free tiers of Smallpdf/iLovePDF all let you sign a PDF at no cost.

Can I sign a PDF without printing and scanning?

Yes — every method above adds a digital signature directly to the file. No printer or scanner required.

How do I sign a PDF on my iPhone?

Open it in the Files app, tap the Markup (pen) icon, then + → Signature, and place your signature.

Is an electronic signature the same as a digital signature?

Not quite. An “electronic signature” is an image of your signature placed on a PDF. A “digital signature” uses cryptography to verify the signer’s identity. For most everyday documents, an electronic signature is all you need. For more PDF tasks, see how to edit a PDF.

Can I create a signature once and reuse it?

Yes — Preview, iPhone Markup, and Acrobat Reader all save your signature for reuse. You can also save a transparent PNG of your signature and place it in any tool.

Is a signed PDF legally binding?

An electronic signature is legally binding for most everyday agreements in many countries, but some documents require a verified digital signature. Check the requirements of the specific document.

How do I sign a PDF on Windows for free?

Use the free Adobe Acrobat Reader app → Fill & Sign, or a free online tool like Smallpdf.