How to Sign a PDF on Your Phone

Hand signing a paper document

Photo: Scott Graham · Unsplash

Someone sends you a contract, a consent form or a work report to sign and you have no printer at hand. With Sign PDF you can sign it on your phone in a couple of minutes, without printing or scanning.

Step by step

  1. Open the PDF in the tool: go to pdfacil.pro/en/firmar-pdf and choose the file. If it came by email or WhatsApp, download it to your phone first.
  2. Create your signature: in “Draw”, sign with your finger in the box. You can choose the colour (black, blue or red) and the line thickness. If you prefer your usual signature, in “Upload image” pick a photo of your signature on white paper: the background becomes transparent automatically.
  3. Place it: tap the page where you want it. Drag it to move it and use the corner handle to make it bigger or smaller.
  4. Sign several pages if needed: switch page and tap again where it belongs. If you make a mistake, there is “Undo”.
  5. Export the signed PDF and download it or send it with “Share”.

Tips for a neat result

  • Turn your phone sideways to have more room to draw.
  • Sign slowly: the line looks more natural.
  • Make the signature slightly smaller than the space on the document; you can adjust it afterwards.

Visual signature or digital signature

PDFácil adds a visual signature: an image of your signature on the document, just like signing on paper. It is not a certificate-based digital signature. For most consent forms and everyday documents that is enough, but if an official procedure explicitly requires an electronic signature with a certificate, you will need that instead.

Your document is not uploaded to any server: the signature is placed and the PDF is generated on your own phone.

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