How to Sign a PDF on Your Phone (Android and iPhone)

What you need before you start

You don't need a printer, a scanner or a signing app. You need three things:

• The PDF saved on your phone. If it arrived by email, save the attachment first. On iPhone, open the attachment, tap the Share button and choose Save to Files. On Android, tap the download icon on the attachment; it usually lands in your Downloads folder. Files sent in WhatsApp or other chat apps can be saved the same way.
• A web browser. Chrome on Android and Safari on iPhone both work. Nothing to install.
• A minute or two. Signing a one-page form usually takes less time than finding a pen.

If what you have is a paper document rather than a PDF, take photos of the pages and turn them into a PDF with JPG to PDF first.

Step 1: Open the PDF in Sign PDF

Go to Sign PDF and tap the box to choose your file. On iPhone the file picker opens the Files app; on Android it opens your file manager or recent downloads. Pick the PDF and the first page appears as a preview.

The document is opened by your browser on the phone itself. It isn't uploaded to a server, which matters when you're signing a lease, an offer letter or anything with personal details on it.

Use the page arrows under the preview to find the page with the signature line before you place anything.

Step 2: Create your signature

There are three ways to make a signature. Pick whichever looks most like you:

1. Draw it. Choose Draw and sign in the box with your finger or a stylus. Black ink is the safe choice for most documents; blue and red are there if you need them, and you can make the pen thicker if your strokes look thin. If you don't like the result, clear it and try again — most people need two or three attempts on a small screen.
2. Type it. Choose Type, enter your name and pick a style (Script, Brush, Handwriting or Elegant). These styles use handwriting fonts that are already on your phone, so the same name can look slightly different on an iPhone and an Android phone.
3. Use a photo of your real signature. Choose Upload and pick a picture of your signature on paper. Remove white background is switched on by default, so the paper disappears and only the ink is placed on the page.

When you're happy, tap Add signature. You can create more than one, for example a full signature and your initials for documents that ask you to initial each page.

Step 3: Place it, resize it and add the date

Tap Place on page and the signature appears on the page you're viewing. Drag it with your finger so it sits on the signature line, then use the corner handle to make it bigger or smaller. A signature that is roughly the height of the line spacing usually looks natural.

To sign more pages, move to the next page with the page arrows and place the signature again. There's no limit on how many pages you sign or how many times you place your initials.

If the document asks for a date, use the Date panel. Leave the date blank to use today, or pick another date. Choose the format the document expects:

• MM/DD/YYYY — common in the United States
• DD/MM/YYYY — common in the UK, Europe, India and many other countries
• YYYY-MM-DD — the international standard format
• Month D, YYYY — written out, for example October 25, 2026

Tap Add date to page and drag it next to your signature, the same way.

If the PDF also has blanks to fill in — your name, address or a reference number — fill those before you sign. Fill PDF Form handles PDFs with real form fields, and Add Text to PDF lets you type anywhere on a scanned or non-fillable form.

Step 4: Download and check the signed copy

Tap Sign PDF, then Download signed PDF. The new file keeps the original name with -signed added, so you can tell the two apart. On iPhone, Safari saves it to the Downloads folder in the Files app by default; on Android it goes to Downloads.

Open the signed file before you send it. Check that:

• the signature is on the right page and sits on the line, not over printed text
• every page that needed a signature or initials has one
• the date is correct and in the expected format

The signature is flattened into the page, so it can't be dragged off or copied out like a sticker — and it can't be moved later either. Keep your original, unsigned PDF in case you need to fix something and sign again.

Sending it back? If you need to return several documents as one file, combine them with Merge PDF. If the file is too big to attach, Compress PDF can shrink it; our guide on making a PDF smaller for email explains the options.

Tips for a clean signature photo

A drawn signature is quick, but many people prefer their real pen signature. A good photo makes all the difference:

• Use plain white paper. Lined or squared paper leaves lines behind when the background is removed.
• Use a dark pen. A black felt-tip or gel pen gives a clean, solid result. Pale ballpoint ink can come out patchy.
• Sign a little larger than usual. You can shrink it on the page; enlarging a tiny signature makes it blurry.
• Find even light. Daylight from a window works well. Avoid your own shadow and the phone's shadow falling across the paper.
• Hold the phone flat and straight above the paper, then crop the photo close around the signature before you upload it.

If grey patches remain after the background is removed, the paper was probably in shadow. Retake the photo in brighter, more even light.

Is a signature added on your phone legally valid?

A signature added this way is a simple electronic signature: a picture of your signature placed on the document, much like signing a printout and scanning it. Electronic signatures are widely accepted for many everyday documents, such as rental applications, school forms, quotes and many employment and business agreements.

Some documents need more than that. Depending on where you are and what you're signing, certain papers may require a certified or qualified digital signature, a wet-ink signature, a witness or a notary. Property deeds, wills and some court or government filings are common examples.

The rules differ between countries and organisations, so this guide can't tell you what applies to your document. The simplest check is to ask whoever asked you to sign: "Is an electronic signature on a PDF acceptable?" If the document is important and you're unsure, get legal advice.