How to Sign a PDF Document on Android

Adding a digital signature to your PDF is easy if you’re viewing it on your PC or Mac, but what if your need arises when you’re on the go? If you own an Android device, know that you can sign your PDF directly from your device. One solution is to download a third-party app, but if you can’t or don’t want to do that, there are other options you can rely on. This tutorial takes you through those options.

Tip: need to sign a PDF on your iPhone? Here’s how to do it!

1. Use a Dedicated Web Tool

If there’s no Wi-Fi in your vicinity, and you don’t want to use up data to download an app, just use one of the websites that offer the option to sign your documents. One of these sites is SmallPDF, which boasts a collection of tools, including “eSign PDF.”

1. Open your mobile browser and navigate to the eSign PDF tool from SmallPDF.
2. Tap on the “Choose File” button or press the upward arrow to upload it from Dropbox or Google Drive

3. Your PDF will be displayed on the screen, and you have a few options when it comes to signing. You can opt to draw or upload your signature by pressing on the first icon at the top, then “Your Signature” at the bottom.

4. On the next screen, use your finger to draw your signature.

5. Alternatively, tap on “Upload” on the left and upload a file featuring your signature.

6. You can also opt to add just your initials. Tap on the second button from the left at the top of the menu, then “Your Initials.” You’ll get the same two options to draw and upload.

7. If you want to have a digitally written signature, this is also possible by tapping on the third button at the top.

8. Input your name and customize the text. For example, you can change its color.

9. You can add a date next to your signature by pressing on the relevant button.

10. Once you’ve added the signature to the document, use your finger to drag the text where you want it positioned.
11. You can enlarge or shrink the signature by pinching it with your fingers.

12. When everything is the way you want it, tap on the “Finish & Sign” button at the bottom.
13. Wait a few seconds for your document to be ready. Press “Download” to save it to your phone.

14. It’s possible to add multiple signatures to the document. Tap the “Signature” button again and select “Add Signature.”

15. Both signatures will be available to you as long as you do not terminate the session. If you want to save these signatures, you’ll need to make an account with SmallPDF.

SmallPDF is not the only online tool you can use to sign a document on Android for free. You can try other options, such as ILovePDF and Sejda.

Good to know: don’t know where your downloaded files are hiding on your Android device? We show you how to find them.

2. Take Advantage of Your Phone’s Built-in Options

Some Android phones – for instance, Samung phones – come with a built-in option that allows you to sign a PDF. Here’s how to use that function:

1. Find the PDF in question on your device (via the Files app) and open it using Samsung’s preinstalled Notes app (PDF reader).
2. Press on the “Pencil” icon in the upper-right corner.

3. You’ll notice a menu of markup options at the bottom. Tap on the first icon to select the type of pen you’d like to write with, as well as the pen’s color and thickness.

4. Use your finger to handwrite the signature directly where you want it on the PDF.
5. You won’t be able to resize the signature once you’ve created it, so make sure you are careful when drawing it, or else you will have to start the process all over again.
6. Press “Save” to save your signed document.

7. If your PDF has arrived via Gmail, you can go straight to adding a signature directly from the mail app.
8. Press on the File icon and select the Samsung Notes (PDF Viewer) option to go straight to the app. Follow steps #2 through #4 to create a signature for your document.

Tip: is your phone’s battery draining fast? Stopping Android apps from running in the background may help reverse that trend.

3. Download a Third-Party App

As a last resort, you can download a third-party app on your Android device to create your signature. There are many that offer the option. Chances are you might have a suitable app already on your device but aren’t aware it offers the option. One such example is OneDrive.

1. Go to the Files app on your phone and find the PDF in question. We’ve used a OnePlus device for this tutorial, so the steps might differ a bit depending on your own smartphone model.
2. Long-press on the PDF, tap on the three dots in the upper-right corner and select “Open with.”

3. Tap on “OneDrive PDF Viewer.”

4. The PDF will open in the app. Tap on the “Pencil” icon in the lower-right corner of the display.

5. Select one of the pens displayed underneath the PDF.
6. Press on the three dots in the upper-right corner and opt for “Signature.”

7. Draw your signature with your finger. You can also opt to “Store signature” for later use.

8. Tap on the “Tick” button in the upper right to go back to the document.
9. Drag the signature to where you want it, then press “Done.”
10. Tap on the “Cloud” button in the upper right to save your signed document to the cloud. You’ll need to sign up with a Microsoft account. If you don’t have an account, you will will have to create one.

11. The changes will be saved, and you will be able to view the signed document on your device.

You don’t have to use OneDrive, though, as there are many other options, including Adobe Acrobat Reader, DocuSign, and signNow.

Good to know: if privacy is important to you, you may want to learn how to unlock Android’s Safe Folder and move all of your sensitive documents there.

Frequently Asked Questions

Does Android have any built-in markup tools?

Not for PDFs, unfortunately. Unless your phone’s manufacturer has specifically added this option, like Samsung. There are markup tools for images, however. If you don’t need to send the PDF back in this exact format, you could take a screenshot of the document you need to sign, open it in the phone’s Gallery, then use the built-in markup tools to draw a signature on the image.

Why do some PDFs not allow me to sign?

If you aren’t allowed to sign a particular PDF, it might have to do with the document’s security certificate. You can check its security options by using your PDF-editing software, but this means you may need to get to a computer to do that. Alternatively, ask the author whether there are any restrictions placed on the PDF and request an unlocked version.

If you have access to a Windows PC, this is another way to get your PDF signed.

How do I scan a signature on Android?

If you’d rather use a signature that you’ve personally handwritten on a piece of paper, you can easily scan it using your Android mobile device and the Google Drive app (which is preinstalled on many Android phones).

Image source: Unsplash. All screenshots by Alexandra Arici.