# How to sign a PDF on iPhone, Android, Mac and Windows

> The built-in way on each platform, what each one is missing, and when you need a signature request instead.

Canonical page: https://bettrpdf.com/blog/how-to-sign-a-pdf-on-any-device  
This file: https://bettrpdf.com/blog/how-to-sign-a-pdf-on-any-device.md  
Site index for agents: https://bettrpdf.com/llms.txt

Published 2026-10-19.

Signing a PDF yourself is a solved problem on every platform. The differences are in what the signature proves, and in whether you can get someone else to sign.

## iPhone and iPad

Open the PDF in Files or Mail, tap the markup pen, tap plus, choose Signature. Draw once and it is saved for next time. Drag it into place and export. The result is a picture of a signature on the page.

## Android

Google Drive's PDF viewer has an annotate mode with a pen; Adobe Acrobat Reader is free and has a Fill and Sign tool that saves a signature. Either way the result is the same picture on the page.

## Mac

Preview, markup toolbar, Sign. You can draw with the trackpad or hold a signed piece of paper up to the camera. Drag into place and save.

## Windows

Edge opens PDFs and has a draw tool but no saved signature. Acrobat Reader's Fill and Sign is the usual answer. Or use a browser tool.

## In a browser, any device

BettrPDF's Fill & Sign works in any browser: type into the form, draw the signature, click where it goes, then download it or send it straight back from your own email.

## When a picture is not enough

All of the above produce a simple electronic signature, valid under ESIGN and eIDAS for most everyday documents, with no evidence beyond the picture. If someone else has to sign, or if you may need to prove who signed and when, you need a signature request with an audit trail. That is planned for BettrPDF Pro; until it ships, use a dedicated e-signature service for those documents.