How to Sign a PDF on Your Phone

A form arrives by email and asks for your signature. Printing it, signing it, scanning it and sending it back takes ages. You can do the whole thing on your phone in a couple of minutes, with no app to install.

This guide explains how, and it also explains what a signature added this way is and is not, so you know when it is enough.

What you need

• The PDF on your phone, usually in your Downloads folder or in your email
• About two minutes
• A finger, or a pen if your phone supports one

Step 1: Open the Sign PDF tool

Open our Sign PDF tool, tap the box and choose the PDF. Your file stays on your phone. It is not uploaded anywhere.

After the file loads, you will see two parts: a place to create your signature and, below it, your pages.

Step 2: Create your signature

You have three ways to do it. Pick the one that suits you.

Draw it

Open the Draw tab and write your signature in the box with your finger. The line is smoothed so it looks natural. Made a mistake? Tap Undo to remove the last stroke, or Clear to start again. Tap Use this signature when you like it.

Tips for a good drawn signature:

• Turn the phone sideways for a wider box.
• Sign a little larger than you think you need. You can make it smaller later, but you cannot add detail.

Type it

Open the Type tab, type your name and choose one of the handwriting styles. This is the quickest option if drawing is hard on your screen. The styles use Latin letters. If your name is written in another alphabet, use the Draw tab instead.

Upload a picture

If you already have a picture of your signature, for example a photo of it signed on white paper, use the Upload tab. Choose the picture and leave “Remove the white paper background” ticked. The paper turns see-through and only the ink is kept. If marks from the paper remain, move the slider up. If your pen lines get thin, move it down.

For the best result, sign with a dark pen on plain white paper, in good light, and take the photo straight from above.

Step 3: Put it on the page

Tap Add signature to page. The signature appears on the page you are looking at. Now:

• Drag it to the right place, such as the signature line.
• Resize it with the round handle at the corner, or by pinching with two fingers.
• Select it by tapping, and remove it with the small red cross.

Need more than one? Scroll to another page and tap Add signature to page again. You can sign as many pages as you like.

Initials and a date

Many contracts ask for initials on each page and a date next to the signature. Open “Add initials or a date” and fill in what you need. Initials are drawn in the handwriting style you chose in the Type tab. The date starts with today’s date and you can edit it before you add it.

Step 4: Save the signed PDF

Tap Save signed PDF, then Download. The signature becomes part of the page. It is not a form field, so it cannot be moved around by accident when the file is opened.

Open the downloaded file once and check:

• the signature is on the line and not over the text
• every page that needs a signature or initials has one
• the date is correct

What kind of signature is this?

This is worth understanding.

The tool adds a picture of your signature to the PDF. This is called a visual or electronic signature. Many everyday situations accept it: a permission slip, a quote you agree to, an internal company form, a rental agreement between friends.

It is not a certified digital signature. A digital signature uses a certificate and cryptography to prove who signed and that the file has not been changed afterwards. Some banks, government offices and legal processes require one. This tool does not create that kind of signature.

Rules about what counts as a valid signature differ between countries and between organisations. If you are unsure, ask the person or office that asked for the signature what they accept. We cannot tell you what is valid for your case.

Keeping your signature safe

A picture of your signature can be copied by anyone who has the signed file. Some simple habits help:

• Only sign documents you have read and trust.
• Send signed files only to the person who needs them.
• Delete extra copies you no longer need.

The signature you create here is never uploaded, and the tool does not keep it. When you close the page, it is gone.

Make the file smaller before you send it

Signed files sometimes grow if the PDF has many pages. If an email or form says the file is too large, use Compress PDF afterwards. If you need to send the signed form together with other papers, join them with Merge PDF. And if your signed document is a set of photos, make them into a PDF first with JPG to PDF.

Troubleshooting

The page scrolls when I try to draw. Draw inside the box only. Inside it, your finger draws instead of scrolling.

My signature looks jagged. Draw a bit slower, or turn the phone sideways for a bigger box.

The upload has a grey box around it. Raise the background removal slider, or take a new photo in brighter light.

Quick checklist

1. Choose the PDF.
2. Draw, type or upload your signature.
3. Place it and resize it.
4. Add initials and a date if needed.
5. Save, then open the file and check every page.
6. Ask the receiver if a picture signature is enough.