How to Sign a PDF Online for Free

The old way to sign a document — print it, sign with a pen, scan it back in — wastes paper, needs a printer and scanner, and produces a crooked, low-quality result. You can skip all of it. Adding a signature to a PDF is just placing an image (your signature) onto a page, which any modern browser can do without installing anything.

The key advantage of doing it in the browser is privacy: a contract or form often contains sensitive personal details, and with a client-side tool the file never leaves your device — no upload to someone else's server.

First you need a signature image with a transparent background so it sits cleanly on the document. The quickest way is a signature maker: draw your signature with a mouse, trackpad, or finger on a touchscreen, or type your name in a handwriting-style font, then download it as a transparent PNG.

A transparent background matters — a signature on a white box will cover up whatever it's placed over. Save the PNG somewhere you can find it for the next step.

Open your PDF in a browser-based PDF signer, add the signature image, then drag it to the signature line and resize it to fit. Position it precisely over the line rather than near it, and keep it a sensible size — an oversized signature looks unprofessional. If the document needs a date or initials, add those as text.

When it looks right, export the signed PDF. Because everything happened locally, the document you download is the only copy of the signed version — nothing was stored elsewhere.

Placing a signature image is an electronic signature, which is legally valid for most everyday agreements. For high-value or regulated documents that require a tamper-proof, certificate-backed digital signature, use a dedicated e-signature platform instead — see the guide on electronic vs digital signatures for the distinction.

For everything else — leases, permission slips, letters, freelance contracts — the two-step browser method above is faster, free, and private.