Signing a PDF on Android is easy with either a dedicated app or a browser-based tool — and unlike iOS, Android gives you more flexibility in how you handle downloaded files. Here are the most reliable methods.
How to Sign a PDF on Android Using WukongPDF
Open Chrome on your Android device and go to WukongPDF's PDF Sign tool. Tap the upload button and select your PDF from your device storage or Google Drive. Tap where you want to place the signature, then draw it with your finger, type your name in a signature font, or upload a photo of your handwritten signature. Adjust the size and position, then download the signed PDF.
The signed file saves to your Downloads folder. From there you can share it via email, WhatsApp, or any other app using the standard Android share sheet.
Signing a PDF With Adobe Acrobat on Android
Adobe Acrobat for Android is free and handles PDF signing well. Open the app, tap the PDF you want to sign, then tap the pencil icon and select Fill & Sign. Tap the signature icon in the toolbar, draw or type your signature, and tap Done. Tap on the page where you want to place it, resize if needed, and save.
Acrobat saves your signature for reuse — useful if you sign documents regularly. Once created, your signature appears in the Fill & Sign panel and can be placed on any document without redrawing.
Signing With a Stylus on Android
Android devices with stylus support — Samsung Galaxy S Ultra with S Pen, or any device with a compatible stylus — give you a much more natural signing experience. In WukongPDF's PDF Sign tool or in Adobe Acrobat, selecting the draw option and signing with a stylus produces results that closely match a handwritten signature.
Samsung's S Pen in particular works seamlessly in the browser-based sign tool — the pressure sensitivity and fine tip make the signature look clean and consistent across multiple signings.
Signing a PDF Sent via Email on Android
When you receive a PDF by email that needs a signature, tap the attachment to download it, then open it with your preferred PDF app. In Gmail, tapping a PDF attachment gives you the option to open it directly in Adobe Acrobat if it's installed. Sign using the app's signature tool, then share the signed file back by email from within the app.
Alternatively, download the attachment, upload it to WukongPDF's PDF Sign tool in Chrome, sign it there, and send the downloaded signed file as a reply attachment. This two-step approach is slightly slower but gives you more control over placement and appearance.