Sign PDF · 3 min read

How to Add a Digital Signature to a PDF — Free

Adding a digital signature to a PDF is the fastest way to sign documents electronically — without DocuSign, Adobe Sign, or any paid service.

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What "Digital Signature" Usually Means

For most people, "digital signature" means a handwritten-style mark drawn with a mouse or finger. This is technically an "electronic signature" and is legally valid for most contracts.

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Step 1 — Open the Sign PDF Tool

Go to pdfeditor.onl/sign-pdf. No account, no subscription, no software installation.

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Step 2 — Create Your Signature

Draw your signature using a mouse, trackpad, or touchscreen. Or type your name in a handwriting font. Or upload a PNG image of your physical signature.

Tip: The canvas supports variable line width — press harder with a stylus for thicker strokes, lighter for thin ones.

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Step 3 — Place and Download

Drag the signature to the signature field on any page. Resize to fit. Click Download Signed PDF.

Add Digital Signature to PDF — Free →

Frequently Asked Questions

Is an electronic signature the same as a digital signature?

Not technically. An electronic signature is a visual mark. A digital signature uses cryptographic keys from a Certificate Authority. For most everyday contracts, an electronic signature is sufficient and legally valid.

Can I sign a PDF on my phone?

Yes. The tool works fully on iPhone (Safari) and Android (Chrome).

Is this free?

Yes — completely free at pdfeditor.onl/sign-pdf.

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