How to Sign a PDF on Android (3 Easy Ways)

Someone sends you a lease, a client agreement or a school form, and all you have is your phone. If you're wondering how to sign a PDF on Android without printing it, signing on paper and scanning it back, you have a few good options. Android doesn't have one standard signing tool built into every phone the way some other systems do, so the right method depends on which apps you already use. This guide walks through each option step by step, explains the trade-offs, and shows a quick way to sign your own PDF in the browser at no cost.

Before you start: get the PDF onto your phone

Every method below starts with the same step: the PDF needs to be somewhere your apps can open it.

Email attachment: In Gmail or another mail app, tap the attachment and save it to your phone or to Google Drive.
Text message or chat: Long-press the file and choose to download or save it.
Website or portal: Download the PDF in Chrome. It usually lands in your Downloads folder, which you can find in the Files app.

Before signing, scroll through the whole document once. Look for every signature line, initials box and date field, so you don't send it back half-finished.

How to sign a PDF on Android with Google Drive

If your phone has Google Drive, and most Android phones do, you can mark up a PDF without installing anything new. Drive offers two separate tools: one for drawing on the page and one for typing into form fields.

Draw your signature with the annotate tool

According to Google Drive Help on annotating PDFs on Android, the steps are:

Open the Google Drive app and tap the PDF to preview it.
Tap the annotate button in the bottom-right corner.
Choose the pen or marker, pick a thin brush and a dark color, and sign with your finger or a stylus.
Use undo or the eraser if the first attempt looks shaky.
Save. You can overwrite the original or save a new copy with a new name, which leaves the original unmarked.

Google notes this feature needs Android 6.0 or later. Zoom in on the signature line before you draw. A signature drawn at full-page zoom often ends up too big or crooked.

Type into form fields

If the PDF has fillable fields for your name, address or date, Google's instructions for filling out PDF forms in Drive say to open the PDF, tap Edit, then Form Filling, enter your details and tap Save. If you don't see the Form Filling option, that PDF may not have fillable fields, and you can use the annotate tool to write in the blanks instead.

Other ways to sign on Android

Drive works for quick jobs, but it has limits. Drawing with a marker tool doesn't save your signature for reuse, so you redraw it every time, and placing it neatly on a small line takes some patience. Here are the other common routes:

A dedicated PDF app. Many PDF reader apps in the Google Play Store include a "fill and sign" mode that saves your signature and lets you tap to place and resize it. Most ask you to create an account.
Your phone maker's apps. Some Android phones, especially ones with a built-in stylus, include their own note or PDF tools with pen support. Options vary by model.
A browser-based e-signature tool. You upload the PDF in Chrome, add your signature and download the signed file. Nothing to install, and it works the same on any phone.

Method	Install needed?	Saves your signature?	Good for
Google Drive annotate	Usually no	No	One-off documents
Google Drive form filling	Usually no	Not a signature tool	Typing into fillable fields
PDF reader app	Yes	Often yes	Frequent personal signing
Browser e-signature tool	No	Depends on the tool	Signing yourself or sending to others

Sign your own PDF in the browser with ReadyInk (free)

ReadyInk's Just me option is free self-signing: signing your own document costs nothing. It runs in your phone's browser, so you don't need to install an app. Here's how it works:

Open ReadyInk in Chrome and upload the PDF from your phone or Drive.
ReadyInk's AI places the fields on the document for you, so you don't have to drag tiny boxes around on a small screen.
Review the fields, then type or draw your signature.
Download the signed PDF and send it back however the other person asked for it.

Not having to place fields yourself is the main time-saver on a phone. Pinching, zooming and nudging a signature box onto a thin line is the most frustrating part of signing on a small screen. If you sometimes sign on an iPhone too, our guide on how to sign a PDF on iPhone covers Apple's built-in tools. On a computer, see how to sign a PDF online.

When other people need to sign

Signing a PDF yourself is one thing. Getting a client, tenant or new hire to sign is another. Emailing a PDF and asking someone to figure out annotate tools usually leads to blurry photos of printed pages and missing initials.

With ReadyInk you can send documents for signature straight from your phone:

Signers don't need an account. They open a link, review and sign.
You review before anything is sent. The AI places the fields, and you check them first.
Reminders and extra copies don't use tokens. Send a copy to your bookkeeper or a reminder to a slow signer at no extra cost.
Templates for repeat forms. Turn a PDF you send often into a reusable template with signer roles, fields and intake questions.

Adding anyone besides yourself uses 1 token per signer. One token covers one signer on one document. Packs start at $10 for 20 tokens, and the Volume pack is $100 for 400 tokens, or $0.25 each. Purchased tokens never expire, and failed sends are refunded. Small teams can use the Team plan at $15/month for 3 users with 30 shared monthly tokens. See e-signature for small business for more.

Whether a particular signing method is right for a specific contract depends on the document and where you are. If that matters for your situation, check with your attorney.

Tips for a clean signature on a small screen

Turn the phone sideways for more room when you draw.
Use a stylus if you have one. Even a cheap one helps.
Zoom in first so the signature fits the line.
Save as a new copy so you keep the unsigned original in case you need to redo it.
Check the file you're sending. Make sure you attach the signed copy, not the original download.

Frequently asked questions

Does Android have a built-in way to sign PDFs?

Not one standard tool on every phone. Most Android phones include Google Drive, which can draw on a PDF with its annotate tool and fill in form fields. Some phone makers add their own pen tools as well.

Can I sign a PDF on Android without downloading an app?

Yes. You can use Google Drive if it's already on your phone, or a browser-based tool. ReadyInk's Just me self-signing runs in Chrome and is free for signing your own documents.

How do I send a PDF to someone else to sign from my Android phone?

Upload it to an e-signature tool, add the signer's email and send a signing link. With ReadyInk, the AI places the fields, you review them, and the signer doesn't need an account. Each additional signer uses 1 token.

Signing a PDF on Android takes a minute or two once you know where the tools are. To skip placing fields by hand, sign your own documents with free self-signing, or send PDFs to others with reminders and tracking, open ReadyInk at app.readyink.ai in your phone's browser.