How-to
How to Sign a PDF on Android (No Extra App, Usually)
Most Android phones can sign a PDF without installing anything extra, using the Google Drive app's built-in markup tool: open the PDF, tap the pencil icon, draw your signature with your finger, and save. Because Android varies by manufacturer, this is the method most consistently available across phones — not a single OS-wide feature the way iOS has.
Sign it yourself, right now (Google Drive's PDF viewer)
- Open the PDF in Google Drive. If it's already in Drive, tap to open it. From a download or email attachment, tap Share or Open with, and choose Google Drive (or Drive PDF Viewer, on phones where it's listed separately).
- Tap the edit (pencil) icon. It's usually a floating button in the bottom-right corner of the PDF viewer.
- Choose the pen tool and sign. Draw your signature with your finger directly on the signature line. Some versions also offer a text tool with a script-style font if you'd rather type your name.
- Save it. Tap the checkmark (or Save) to write the signature into the document.
- Share the signed copy. Use the share icon to email or message it back, or download it to your device from Drive's menu.
On a Samsung phone, Samsung Notes' PDF import and markup tools work the same way and are also worth checking if you already use Notes for annotating documents.
Common mistakes
- Editing a view-only copy. If the PDF was shared with you as "view only" in Drive, make a copy first (File > Make a copy) — the edit tool won't let you save markup onto a file you don't have edit access to.
- Forgetting which app actually saved the signature. If you opened the PDF through a different app's own "open with Drive" flow, double-check the signed version landed back where you expect before sending it anywhere.
- Using this for someone else's signature. This method only signs a copy on your own phone — it doesn't send the document anywhere or prove when someone else signed it. See below for when that distinction matters.
When this isn't enough
Drive's markup tool is the right call when you're the only one signing and the document already exists on your phone. It's not built for the other, more common situation: getting someone else's signature — a client accepting a quote, a vendor countersigning terms — since it has no way to send the document out, notify you when it's been opened, or prove when and how the other person signed.
That's what a dedicated tool like DocuAgree adds: build or upload the document once, add the other person's email, and they get a link to sign from their own phone, no app or account needed on their end. You get a certificate of completion and a full audit trail the moment they finish.
General guidance based on the Google Drive app's current behavior. Exact icon placement varies by Android version and manufacturer skin (Samsung One UI, Pixel, and others each style this slightly differently).