How to Sign a PDF on iPhone, iPad & Android for Free (2026)

You are away from your desk, on a train, or at a cafe, and an urgent agreement lands in your inbox. In the past, signing a document meant waiting until you got home to a printer and scanner. Today, you can complete the entire process directly from your mobile device.

If you need to complete an e signature pdf online or perform a complete mobile edit and sign pdf flow, you do not need to purchase expensive office software. In this guide, we show you exactly how to sign document for free on any iPhone, iPad, or Android device in under two minutes.

---

Method 1: iPhone & iPad Built-In Markup (iOS 17 & 18)

If you use an Apple device, iOS and iPadOS include a built-in feature called Markup. This allows you to draw and save signatures in the default Files and Mail apps:

1. Open the PDF document in the **Files** app on your iPhone or iPad.
2. Tap the **Markup** icon (it looks like a marker or pen tip inside a circle) in the top-right corner of the screen.
3. Tap the **+** (plus) button in the bottom-right toolbar.
4. Select **Add Signature** from the menu.
5. Draw your signature on the screen with your finger or an Apple Pencil. Tap **Done** to save it.
6. Drag your signature to the correct signing line and pinch to resize it.
7. Tap **Done** in the top-left corner to save the signed PDF.

Limitations: iOS Markup only works on local files in the Files app or email attachments in Mail. If you need to edit text fields, check checkboxes, or if you receive a file on WhatsApp, it can be difficult to use Markup. It also does not support typed signatures.

---

Method 2: Google Drive & Samsung Notes (Android Ecosystem)

Android users have native ways to sign depending on their device manufacturer:

Google Pixel and standard Android:

1. Open the PDF document inside the **Google Drive** app.
2. Tap the **Edit** (pencil icon) button in the bottom-right corner.
3. Select the Pen tool and choose your preferred ink color.
4. Draw your signature directly onto the page.
5. Tap **Save** in the top-left corner to update the document.

Samsung Galaxy Phones:

1. Open the PDF inside the **Samsung Notes** or **Samsung PDF Reader** app.
2. Tap the pencil icon to enter edit mode.
3. Select the Pen tool and draw your signature on the document.
4. Save the document to your local storage or SD card.

Limitations: Android native tools vary greatly between different operating system versions and phone brands. They also lack security features, such as cryptographic seals, and sync files automatically to the cloud, which might violate business privacy guidelines for sensitive contracts.

---

Method 3: MyDigitSign (Universal Mobile Web App)

For the most reliable, private, and feature-rich experience, MyDigitSign works in any mobile browser (Safari, Chrome, Samsung Internet, Firefox) on both iPhone and Android. It operates as a full-featured client-side pdf editor signature tool.

1. Open your mobile browser and go to the Free Sign PDF online tool.
2. Tap the upload box and select your document from your camera roll, Files app, or downloads folder.
3. Tap **Sign** in the toolbar to create your signature:
   • Draw tab: Touch the canvas to draw a natural signature with your finger. We optimize the line curves so they look clean even on small screens. Try drawing online →
   • Type tab: Type your name and select a beautiful cursive font style. Create typed signature →
   • Upload tab: Take a photo of a physical signature on a sheet of paper and let our tool remove the background automatically.
4. If you need to fill out text fields or dates, tap **Add Text** in the menu bar to type directly on the PDF. This makes it easy to edit and sign pdf forms at the same time.
5. Position and scale your signature on the signing line, then tap **Download Signed PDF**.

Your documents are never sent to external servers. All rendering and cryptographic signatures are processed directly in your mobile browser's memory using WebAssembly, ensuring 100% data security.

---

Comparison: Mobile PDF Signing Options

---

Tips for Signing PDFs on Mobile Touchscreens

• Pinch to Zoom: On a small screen, pinch out to zoom in on the signature field. This makes drawing your signature with your finger much easier and more precise.
• Rotate to Landscape: Rotate your phone horizontally to give yourself a wider drawing canvas.
• Use cursive text if drawing is hard: If you find drawing on glass frustrating, switch to the 'Type' signature tab. Cursive text looks clean and consistent on contracts.
• Use stylus support: If you have an Apple Pencil, a Samsung S-Pen, or a cheap capacitive stylus, they will work perfectly with our canvas.

Are Mobile Electronic Signatures Legally Binding?

Yes. The type of device you use does not affect the legality of your signature. Under the US **ESIGN Act** and European **eIDAS** regulations, any electronic signature carries the exact same legal weight as a paper-based ink signature, provided there is intent to sign and document integrity.

Using MyDigitSign ensures that the document cannot be tampered with after signing, which provides strong legal authenticity in court. Read more about e-signature legality in our are electronic signatures legally binding guide.