How to sign a PDF for free
Published on September 09, 2026
A contract or form arrived as a PDF and you don't need to print it, sign with a pen and scan it back. You can sign right on screen, for free, by drawing or uploading an image of your signature. Here's how to do it — and the difference between a signature that's only visual and one with legal validity.
Signing without printing: how it works
Signing a PDF on screen is basically placing an image of your signature over the document, in the right spot. You can draw the signature with your mouse or finger, type your name in a signature font, or upload a photo of your signature done on paper. Then you just position it over the line and save. The result is a PDF ready to send back, with no printer, no scanner and no software to install.
How to sign a PDF on AtlasDocs
- Open the Sign PDF tool.
- Upload the document that needs your signature.
- Draw, type or upload your signature image and click the page to place it — you can place as many as you need, on any page.
- Drag to fine-tune the spot, pick the size and click Sign and download.
Everything happens inside your browser: the document is signed on your own device and is never sent to any server. Your contract never leaves your computer.
Visual signature vs. legally valid signature
It's important to understand this difference. A signature drawn or pasted onto the PDF is a visual signature: it handles everyday needs, makes the document look signed and works for many agreements between parties who trust each other. But on its own, it doesn't carry technical proof of who signed or that the file wasn't changed afterward.
A legally valid signature (an electronic or digital signature) adds that layer: it ties the signature to your identity and seals the document, so that any later change can be detected. That's what provides security in more formal contracts and in documents that could be challenged.
How to add legal validity in Brazil, for free
In Brazil there's a free, official route. After positioning the visual signature, you can sign the same PDF with legal validity through the government's signer at assinador.iti.br, using your gov.br account. The higher your gov.br account level (silver or gold), the stronger the legal weight of the signature. That way you combine the best of both: the signature in your own hand, done here, and the official government seal on top.
For everyday use, signing on screen is enough. For important contracts, it's worth taking that extra step to make sure the signature carries legal weight.