How to Sign a PDF on Your Phone Without an App

Someone emails you a PDF with "please sign and return", and you're away from a printer. You can sign it on your phone: open the PDF in your browser, draw your signature with your finger, place it on the signature line, and download the signed copy. No app, no account.

Before you start, it helps to know what kind of signature this is, because it affects where it's accepted.

What kind of signature you're creating

Signing with a drawn, typed or image signature creates a simple electronic signature: a visual mark of your signature on the page. It is not a certificate-based digital signature, the kind issued by a certification authority that cryptographically proves who signed and that nothing changed afterwards.

For everyday paperwork, such as a lease renewal, a school permission slip, an internal approval or a freelance contract, a visual signature is often what the other person expects. Some processes set their own rules. The U.S. Tax Court's DAWSON guide, for example, accepts imaged or digitized signatures on PDFs in some situations, but limits stylized signatures such as "/s" or a cursive font. When it matters, ask the recipient what they accept, or read the instructions that came with the form.

Sign step by step

1. Open Sign PDF in your phone's browser and choose the PDF from your files or downloads.
2. Create your signature. Pick one of three ways:
   • Draw it with your finger. Turn your phone sideways for more space.
   • Type your name and pick one of three handwriting-style fonts.
   • Upload a photo of your signature on white paper. There's an option to remove the white background so only the ink shows.
3. Go to the right page and tap to place the signature.
4. Move and resize it so it sits on the line, about the size of a handwritten signature.
5. Add text if needed, such as your printed name or the date next to the signature.
6. Repeat on any other page that needs a signature or initials. You can place the signature as many times as you need.
7. Download the signed PDF.

Sign PDF runs in your browser, so the document and your signature stay on your phone. It's for your own signature only. It doesn't send requests for other people to sign.

Tips for a signature that looks right

• Draw slowly with a steady finger. Fast strokes on a small screen come out jagged.
• Use the upload option if you want your real pen signature: sign on white paper, photograph it in good light, upload it and remove the background.
• Keep the size realistic. A signature twice as big as the line looks pasted on.
• Don't cover printed text. Zoom in to check that the signature doesn't hide the line label or date field.

If the PDF has form fields

Many contracts and applications have fields for name, date and checkboxes. Fill those in with PDF Forms, which fills in existing text fields, checkboxes, option buttons and dropdown lists. Then sign. If you don't want the recipient to be able to change the entries, use the flatten option, which turns the fields into regular page content. Note that the forms tool doesn't detect fields automatically: it fills the fields that are already in the PDF, or you can draw new ones.

If you only have a paper copy

If someone handed you paper, sign it with a pen and then use Scan to PDF to capture the pages with your camera. Crop each page by its corners, use the black-and-white filter so the ink stands out, and download the PDF. Some processes explicitly accept this: the DAWSON guide, for example, says PDFs of documents printed and signed by hand are acceptable.

Before you send it back

• Open the downloaded file and check every signature is on the right page and line.
• Check the date you added, if any.
• Consider a password if the document is sensitive and you're sending it by email. Protect PDF adds AES-256 encryption with an open password. Send the password on another channel, such as a text message. Don't do this for official portals that forbid protected files.
• Name the file clearly, such as lease-renewal-signed-2026-09-30.pdf, so nobody confuses it with the unsigned version.

When two people need to sign

Sign PDF adds your own signature. It doesn't route a document to other signers. If a second person must sign, the simplest approach is sequential: you sign and download, send the signed file to them, and they add their signature the same way on their own phone. Agree in advance who signs first, and use a file name that shows the status, such as agreement-signed-tenant.pdf and then agreement-signed-both.pdf.

Common mistakes

• Signing the wrong version. Check you downloaded the latest draft before signing.
• Missing initials on pages that ask for them. Search the document for "initial" or check the footer of each page.
• Assuming it's a certified digital signature. It isn't. If the recipient requires a certificate-based signature, use the system they specify.
• Sending an editable form. Flatten filled forms if the content shouldn't change.

Checklist

• The recipient accepts a simple electronic (visual) signature.
• Fields filled in first, then flattened if needed.
• Signature placed on every required page, at a realistic size.
• Downloaded file opened and checked.
• Clear file name, and a password only if appropriate.