Add Signature to PDF

Why not uploading matters here specifically

Consider what the upload-based signing tools ask for. You send them the document, which is usually a contract, a lease, an offer letter or a consent form. And you send them an image of your signature.

That second part is the one worth pausing on. A signature image is reusable — it can be placed on any document by anyone who has it. Handing a copy to a free web service in exchange for one signed PDF is a poor trade, and it is the trade almost every tool in this category asks you to make.

Here the PDF is read and rewritten on your own machine, and the signature you draw never leaves the page it was drawn on.

Draw it on a phone

A signature drawn with a mouse looks like a mouse drew it. On a phone or tablet, drawn with a finger or a stylus, it looks like a signature — and that is the whole point of a handwritten mark. The drawing canvas here handles touch properly, so this is one of the few cases where doing the task on your phone gives a better result than doing it at a desk.

If you would rather type, the Type tab sets your name in a script or print face and renders it as the signature. And if you already have a signature image — scanned, or drawn once and kept — the Upload tab takes it.

One practical note on uploading: draw it here, or upload a PNG with a transparent background. A photographed or scanned signature saved as a JPG carries its own background with it, so it lands on the page as a pale rectangle sitting over whatever is underneath. A signature drawn or typed here comes out with a transparent background automatically and sits cleanly on the page.

Click the page to put it where it belongs

Once the PDF loads you get the actual rendered pages, with thumbnails to jump between them. Click where the signature should sit and it goes there — the click marks its centre, and a marker shows you the spot before you commit.

That matters because signature blocks are rarely in the bottom-right corner. They are next to a printed name, inside a box, on page four of seven, above a date line. Bottom Right, Bottom Center and Bottom Left are there as presets when the document is simple, and you can apply the signature to just the page you are looking at, the last page, every page, or a custom range like 1,3,5-8 for a document that needs initialling throughout. The size slider runs from 50 to 300 pixels wide.

What kind of signature this is — and when you need something else

This places an image of your signature onto the page. That is what people mean by signing a PDF the overwhelming majority of the time, and it is accepted for most everyday documents: rental agreements, school forms, freelance contracts, internal approvals, delivery sign-offs.

It is not a certificate-based digital signature. There is no cryptographic certificate binding the signature to a verified identity, no record of who signed or when, and no tamper-evident seal on the document afterwards. Tools like DocuSign and Adobe Sign exist to provide exactly those things.

So the practical question is what the other side needs. If they asked you to "sign and send it back", this is what they meant. If they specified a digital signature, a certificate, an audit trail, or sent you a link into a signing platform, use what they asked for — and when a document is high-value or a dispute is plausible, it is worth asking rather than assuming.

If the PDF is password-protected

A protected PDF cannot be signed until the protection is removed — the file has to be opened and rewritten to add anything to it. Unlock it first, then sign, then re-protect if it needs to go back out secured.

Related tools

Unlock PDF removes a password or printing restriction so a locked document can be signed. Protect PDF puts a password back on the signed file before you send it, and Merge PDF combines a signed page back into a larger document.