How to sign a PDF on your phone: iPhone and Android, no app
Updated September 5, 2026
The PDF arrives on your phone by WhatsApp or email and needs to go back signed. On a phone that is actually the easiest case, because signing with a finger feels more natural than with a mouse. This guide shows how to add a signature to a PDF on iPhone and Android without installing an app, and what to do when the document only exists on paper.
Signing on an iPhone
Safari is all you need. Nothing to install.
- Open signhere.me in Safari and tap "Choose PDF". Pick the file from Files, from Mail or straight from WhatsApp via Share.
- signhere shows the page and marks the signature lines it found. Tap the spot where the signature goes.
- Draw your signature with your finger in the box. Turn the phone sideways for more room. Tap "Clear" to start over.
- Tap "Done". Save the signed PDF to Files, email it or send it straight back to whoever asked.
Signing on an Android phone
Same flow, in Chrome, Samsung Internet or Firefox.
- Open signhere.me and tap "Choose PDF". Android shows the file manager, Downloads and apps such as Drive or WhatsApp.
- Tap the marked signature line or any spot you like.
- Sign with your finger or the S Pen. Place and date can be filled in at the same time.
- Tap "Done" and save or share the PDF.
Why not photograph your paper signature
Many people photograph their signature on paper and paste the image in. That produces a grey box with shadows, looks bad and can be copied anywhere. Drawing with your finger gives a clean line with no background, scaled to fit the field, and it belongs to this document only. If you prefer a pen, use a tablet or the S Pen.
When the document only exists on paper
Just photograph it. signhere finds the edges of the sheet, crops it, straightens the perspective and turns it into a PDF. Several pages can be photographed one after another and are joined into one document. This also works for forms that arrive by post.
Getting someone else to sign on their phone
Upload the PDF and you get a link. Send it by WhatsApp. The other person opens it on their phone, signs with their finger, and you receive the finished PDF by email. They do not install anything or create an account. For powers of attorney you can also request an ID copy, which they take with their camera on the spot.
Common snags
If something does not work, it is usually one of these.
- The PDF is password-protected: remove the protection or ask for the original.
- The file is an image or a Word document: export it as PDF or simply photograph it.
- The signature comes out tiny: hold the phone sideways for a larger drawing area.
- The link has expired: unsigned documents are deleted after seven days, so request it again.
Try it now
Upload a PDF, tap the spot, sign. Free and without an account.
Upload a PDFFrequently asked questions
Do I need an app to sign on my phone?
No. signhere runs in Safari and Chrome. You can add it to your home screen like an app, then it opens without the browser bar.
Can I sign a PDF straight from WhatsApp?
Yes. Tap the file in WhatsApp, choose Share and then signhere in the browser, or save the file first and upload it.
How do I get the signature to look neat?
Turn the phone sideways and draw slowly. The line is smoothed. Tap "Clear" to start again as often as you like.
Can I add the date and place on my phone too?
Yes. signhere recognises date and place fields and suggests today’s date. You can type free text into any form field.
This guide is general information, not legal advice.