How to sign a PDF without printing it (or a scanner)

Someone asks you to send back a signed document, you open the email… and you don't have a printer handy, or a scanner. The old-school solution —print it, sign it with a pen, and scan it again— is a hassle and, on top of that, it makes the quality worse. The good news is that you can sign the PDF directly, from your computer or phone, without printing or scanning anything.

First things first: there are two kinds of "signing"

It's worth telling them apart, because they get mixed up a lot. On one hand there's the regular signature: your signature, drawn or typed, placed on the document. This covers the vast majority of everyday needs — authorizations, school forms, agreements between individuals, an informal rental contract, sending back a "signed" document. On the other hand there's the digital signature with a certificate (using your electronic ID or a digital certificate), which is the one that carries full legal validity for official procedures with the authorities.

For 90% of the times someone tells you "sign it and send it back to me," what they need is the first kind. This article is about that one. If you're specifically asked for a certificate-based signature for an official procedure, that's done with programs like dedicated signing software and your certificate, which is a whole different story.

How to sign the PDF by hand (or typed)

The process is always similar and takes less than a minute:

1. Open the PDF in the signing tool.
2. Draw your signature (with the mouse, or with your finger if you're on your phone) or type it out and pick a style.
3. Drag it to where it needs to go, and adjust its size.
4. Download the signed PDF. Ready to send.

Little details that look better

• Place the signature right above or next to where it says "Signature," not just anywhere.
• Don't make it huge: a signature that's proportional to the text looks more professional.
• If the document asks for a date, add it yourself next to the signature (many tools let you add text too).
• Check the downloaded result before sending it, in case the signature ended up on the wrong page.

And if you also need to combine that signed document with others, or shrink it because it's too big to send, you can do that without leaving your browser too. Signing without a printer stops being a problem the moment you try it once.