How to Sign a PDF on Android

Phone-maker tools

Some manufacturers include their own PDF or notes apps with drawing tools, for example Samsung Notes on Galaxy devices. These can work, but options vary by model and software version, which is why Acrobat Reader or a browser tool is the easier general answer.

A browser-based option

If you would rather not install anything, eSignSimple's free Sign PDF tool is included with a free account (sign up with Google) and runs in your browser. You upload the PDF (it is encrypted at rest), draw or type a signature, add the date, and download the signed copy with an audit trail; it counts as one of your monthly documents.

It works in Chrome on Android, so you can sign without installing an app.

Troubleshooting: why can't I sign my PDF on Android?

If the PDF opens in Google Drive's viewer or in your browser, you are only viewing it. Use the three-dot menu to choose Open with and pick Acrobat Reader, or download the file first. If Acrobat says the document is protected, the sender has restricted editing; ask for an unlocked copy or ask them to send it through an e-signature service, which puts signature fields on the page for you.

If your signature looks thin or broken, rotate to landscape and draw more slowly. A typed signature is also acceptable in most places, as our guide to creating an electronic signature explains.

Signing yourself vs. getting someone else to sign from Android

Acrobat Reader handles your own signature well. Collecting other people's signatures is a different job: you need a way to send, track and prove it. With eSignSimple you can upload the PDF from your phone's browser, add signers and fields, and send; each signer gets a link and signs without an account. The walkthrough in how to send a document for signature covers the whole flow, and the pricing page shows what the Free plan includes.

On an iPhone the process uses Apple's built-in Markup instead; see how to sign a PDF on iPhone.

Which method should you use on your Android phone?

If you only sign the occasional form, Acrobat Reader is the safe default: one app, the same on almost every phone, and a saved signature you can reuse. If you cannot or do not want to install anything, for example on a work phone with a locked-down app store, a browser tool does the job in Chrome. If your phone maker's notes or gallery app happens to open PDFs with a pen tool, it can work for a one-off, but expect to hunt for the export option.

The choice changes when the PDF is a contract with several parties. Signing on your phone and emailing it back works for one signature. When three people have to sign in turn, a link-based service is faster on Android than passing an attachment around, because each person signs in the browser and nobody has to download, sign and re-attach anything.

Where did my signed PDF go?

This is the most common Android question we hear. Acrobat Reader may save the signed copy back into the original location, into its own app storage, or into Adobe's cloud, depending on where the file came from and how the app is set up. A file opened from an email attachment is often a temporary copy, which is why the signed version seems to vanish when you go back to Gmail.

The reliable habit is to use the share option in Acrobat right after signing and send the file where it needs to go, or save it to Downloads or Google Drive with a clear name. Then open the Files app (often called Files by Google or My Files on Samsung) and check that the signed copy is really there before you reply to anyone.

Signing in the browser on Android: tips that make it smoother

Chrome on Android handles signing links and in-browser tools well, but the small screen needs a little care. Close other tabs if the phone is short on memory, because a large PDF rendered page by page can push older tabs out. Use landscape mode to draw your signature, since the drawing area becomes wider and the line steadier. If the keyboard covers the field you are typing into, scroll the page up slightly rather than closing the keyboard.

If you see a blank page or a loading spinner that never ends, the cause is usually a data saver or a content blocker interfering with the page. Try the link again on Wi-Fi or with the data saver off. For signing on a Chromebook, which shares some Android behaviour but has a full desktop browser, see how to sign a PDF on Chromebook.

Should you trust a free PDF signing app from the Play Store?

Before installing one, look at what it asks for. A signing app needs access to the files you choose; it does not need your contacts, your location or permission to show ads over other apps. Check the developer's name and when the app was last updated, and read a few recent one-star reviews, where problems such as watermarks added to every page or forced subscriptions tend to surface.

Remember that a contract is often the most sensitive file on your phone: names, addresses, salaries, bank details. A tool that processes the file locally, like Acrobat Reader, keeps that data on your device; if you use an online service, including our Sign PDF tool, check that it says plainly how files are stored (we encrypt uploads at rest). If you want to compare options for sending documents out, best free electronic signature software lists what the free tiers really include.

Our take

Sources and further reading

• Fill and sign PDF forms in Acrobat on mobile – Adobe Help
• ESIGN Act, 15 U.S.C. § 7001 – general rule of validity (Cornell LII)