Steps on Android or iPhone
- Save the PDF to your phone (in WhatsApp or Gmail, open the attachment and choose save or download, or keep it in Files).
- Open opensigner.online/sign in Chrome, Safari or any modern browser and tap the drop zone to pick the file.
- Tap Signature and draw with your finger. Turning the phone sideways gives you more room. You can also type your name instead.
- Drag the signature into place and resize it with the corner handle. Add a date or a text field for your name.
- Tap Finalize & export. The signed PDF is saved to your downloads, ready to share back.
Tips for a clean result
- Zoom the page so the signature line is large before placing your signature.
- Use the page selector to jump to the last page, where signature lines usually are.
- Your phone keeps your last signature in the browser, so next time it's one tap.
Private on mobile, too
The file is processed on the phone itself; nothing is uploaded. After your first visit, the app is cached and works even with no signal.