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How to Add a Signature to a PDF on iPhone (Free, No App Needed)
Need to sign a PDF on your iPhone and don't want to download yet another app? You have multiple free options — including one that's already built into iOS.
Method 1: Use iOS Files App with Markup (Built-In — No Download)
This works on any iPhone running iOS 15 or later with no app required:
- Open the PDF in the Files app
- Tap the PDF to open it
- Tap the pencil icon (top-right corner) to open Markup
- Tap the + button → Signature
- Draw your signature with your finger (or Apple Pencil)
- Place and resize the signature on the page
- Tap Done to save
💡 Save Your Signature: iOS saves your signature automatically. Next time, it appears instantly — no redrawing needed.
Method 2: Use Quick Do PDF Online (Any Browser, No App)
- Open Safari on your iPhone
- Go to quickdopdf.com/sign.html
- Tap "Select PDF File" → choose from Files or Photos
- Draw your signature with your finger on the signature pad
- Tap on the document where you want to place it
- Tap "Download Signed PDF"
This works fully in Safari — no installation, no account, no watermark.
Method 3: Sign PDFs in Mail App (Email Attachments)
If someone emailed you a PDF to sign:
- Open the email in the Mail app
- Tap the PDF attachment
- Tap the Markup button (pen in a circle)
- Add your signature using the + → Signature option
- Tap Done → Reply or Forward with the signed PDF
Which Method Should You Use?
| Method | Best For | Requires App? |
|---|---|---|
| iOS Files/Markup | Quick sign, saved locally | No (built-in) |
| Quick Do PDF online | More control, any device | No (browser) |
| Mail app Markup | Signing email attachments | No (built-in) |
| Adobe Acrobat | Professional workflows | Yes (free tier) |
💡 Apple Pencil Users: The Markup method with Apple Pencil produces the most professional-looking signature — nearly identical to writing on paper.
Sign PDFs Free — Works on iPhone
Open in Safari. Sign with your finger. Download instantly. No app needed.
Sign PDF on iPhone →