iPhone guide
Sign a PDF on iPhone.
No app. No signup.
You received a PDF in Mail or WhatsApp and need to sign and return it. There is no need to install an app or create an account. Here is the minute-long way to do it in Safari.
Open pdf2sign1. Save the PDF to Files
Regardless of where the PDF came from — Mail, WhatsApp, iMessage, Safari, Slack — iOS treats it the same way. Tap the attachment to open it full-screen, then tap the share button in the bottom bar (or top-right, depending on the app) and choose Save to Files. Save it in iCloud Drive → Downloads, or On My iPhone → Downloads if you don't use iCloud Drive.
This step exists because iOS browsers can only open files from the Files app, not directly from a chat or email. It takes two taps.
2. Open pdf2sign in Safari
Open Safari and go to pdf2sign.app/sign. Tap the upload area. iOS will open the Files picker; navigate to Downloads (or wherever you saved the PDF) and pick the file.
Safari loads the PDF into the editor. Your PDF never leaves your iPhone — pdf2sign processes everything locally in the browser tab. If you want to verify, turn on airplane mode after the page loads and the full flow still works.
3. Draw your signature full-screen
On iPhone, the signature pad opens as a full-screen overlay so you have room to draw naturally. Use your finger, or an Apple Pencil on iPad (or iPad mini with a compatible Pencil). The pad captures full-resolution strokes, so your signature stays crisp even when you size it down on the page.
Don't like how it turned out? Tap Clear and redo. Prefer a typed signature? Switch to the Type tab and pick one of four handwriting fonts (Dancing Script, Caveat, Great Vibes, Pacifico).
4. Place it, resize it, download
Drag your signature onto the signature line. Pinch or drag the corner handles to resize. Tap and drag to move. When it looks right, tap Download.
Safari will ask where to save the signed PDF — pick Files → Downloads (or wherever's convenient). The signed PDF is now on your iPhone, ready to share.
5. Share the signed PDF back
From Files, long-press the signed PDF and choose Share. You can send it via:
- Mail — as a reply attachment to the original email
- Messages / iMessage — drag into the conversation
- WhatsApp — share icon → WhatsApp contact → send
- AirDrop — to a nearby Mac or another iPhone
- Slack, Teams, Gmail, Outlook — any installed app that accepts PDF attachments
Why sign in Safari rather than an app?
The App Store is full of PDF signers that need a signup, show ads, or cap free use to two documents a month. pdf2sign has none of that because it's a web tool — there's nothing to monetise per-install. The other practical win: because the app is the browser, you don't have to trust a third-party developer with your documents. The file never leaves Safari's tab.
Frequently asked questions
Do I need to install an app to sign a PDF on my iPhone?
No. pdf2sign runs in Safari (or any iOS browser). There is no app in the App Store to install, no permission prompt for Photos or Files beyond the standard file picker.
Can I use the Apple Pencil?
Yes. The signature pad uses the Pointer Events API, which captures Apple Pencil strokes including pressure when your device supports it. Just start drawing on the canvas with the Pencil.
Where does the signed PDF go?
It downloads to the Files app, under iCloud Drive → Downloads by default (or On My iPhone → Downloads if you have iCloud Drive off). From there you can share it back via Mail, Messages, AirDrop, or save it wherever you want.
Does this work on older iPhones?
Any iPhone running iOS 14 or later handles it comfortably. The tool uses standard browser APIs that have been available in Safari for years.
Can I sign a PDF I received in Mail without leaving Mail?
Almost — tap the attachment, then the share icon, tap Save to Files, then switch to Safari and open pdf2sign.app/sign. You can then share the signed PDF back to the original email as a reply attachment.
Can I sign a PDF I received in WhatsApp?
Yes. Open the PDF in WhatsApp, tap the share icon, choose Save to Files, then pick the file from pdf2sign. After signing, share the signed PDF back via WhatsApp.