How to Sign a PDF on Your Phone (No Printing, No App)

October 9, 2026

Got a form to sign on WhatsApp or by email, and there's no printer around? You can sign the PDF right on your phone with your finger, without installing an app and without printing and scanning. The whole thing takes about a minute.

Step 1: Save the PDF on your phone

The file needs to be saved on the device so you can pick it:

• iPhone: open the file in WhatsApp or Mail, tap the share button and choose Save to Files.
• Android: when you pick a file from the browser, recent files, including ones from WhatsApp and Gmail, usually show up. If yours isn't there, open it and choose Download or Save.

Step 2: Sign it

1. Open Sign PDF in your phone's browser and choose the file.
2. Draw your signature with your finger in the box, or switch to Type and enter your name. If the signature comes out wobbly, tap Clear and try again.
3. Choose the page, first or last, and the position: bottom right, bottom left or bottom center.
4. Choose whether to add today's date under the signature.
5. Tap the button and download the signed file.

Tip: if it's hard to draw a neat signature with your finger, turn the phone sideways. The box gets wider and you have more room to move.

Step 3: Send it back

The signed file is saved to your Downloads folder (on iPhone: the Files app → Downloads). Attach it to WhatsApp or an email like any other file. Open it once before sending to check the signature is where it should be.

What if the signature line is in the middle of the form?

The tool adds the signature at the bottom of the first or last page, which is where the signature line sits on most contracts and forms. If yours needs a signature somewhere else, such as a page in the middle, take that page out with Split PDF, sign it, and put the file back together with Merge PDF.

Is a signature like this valid?

For most everyday documents, like forms, consent letters, agreements between private people and rental contracts, a signature added to a PDF is accepted just like one signed on paper and scanned. Some documents require a certified digital signature with a certificate, mainly for government bodies and large transactions. The guide to signature types explains the difference and how to tell what you need. For a lease, see also how to sign a rental contract without printing it.

Privacy

Your signature and the file are deleted from the server automatically after one hour and aren't stored anywhere else. There's no sign-up and no account is created.