How to sign a PDF on Android

Option one: Adobe Acrobat Reader for Android

Acrobat Reader is free on Google Play and is the most dependable way to sign on Android. Open the PDF in Reader (from Files, Gmail or Drive, choose Open with and pick Acrobat). Tap the edit button and choose Fill & Sign. Then tap the signature icon and Create signature, sign with your finger, and tap Done.

Tap where the signature should go, then drag and resize it. The same menu lets you add initials, text and a date. Reader saves the file, and you can share it back from the Share icon. Adobe will ask you to sign in for some features, but filling and signing does not need a paid plan.

Option two: Google Drive's pen tool

If you would rather not install anything, Google Drive on Android can draw on a PDF. Open the PDF in Drive, tap the annotate button (a pen), choose the pen, set a dark colour and a thin brush, and write your signature. Google's help page notes this needs Android 6.0 or later.

This is freehand only. There is no saved signature, so you redraw it each time, and Drive saves the annotated version as a copy. For a fillable form, Drive's Edit > Form filling fills typed fields but does not add a signature.

Samsung and other phone makers ship their own PDF viewers with drawing tools. They work the same way: you draw an image of your signature on the page.

Option three: Google's eSignature, if you have Workspace

Google Docs and Drive have a proper eSignature feature that sends a signing request, but Google lists it only for Workspace Individual and some Business, Enterprise and Education plans, and requests are set up on a computer. If someone sends you a Google eSignature request, you can sign it on your phone by opening the email link, tapping each coloured field, choosing Draw or Type and tapping Adopt and sign.

Collecting a signature from your Android phone

The three options above put your signature on a file. If you are the one asking, say a contractor who needs a client to approve a quote on site, you want the client's signature with proof attached.

Open signpdf.ai in Chrome, upload the PDF or a photo of the printed page (JPG, PNG or WebP), and we place the signature, name and date boxes. Add the client's email and send. They get a link, enter the six-digit code we email them, and sign on their own phone. The sealed PDF records their verified email, IP address, device and the exact time they signed. There is no Android app; it all runs in the browser, from $5 a month.