---
title: "How to sign a PDF on Android, no app needed · Attest"
description: "Sign a PDF on your Android phone in Chrome with your fingerprint, face or screen lock: no app, no printing, and a signed copy anyone can verify."
url: https://attest.datahubz.com/how-to/sign-pdf-on-android
updated: 2026-10-12
---

[Attest](https://attest.datahubz.com/)/[How-to](https://attest.datahubz.com/how-to)

# How to sign a PDF on Android, no app needed

Open attest.datahubz.com/sign in Chrome, sign in with your email and set up your signing key once with your fingerprint, face or screen lock; then tap Sign a document yourself, upload the PDF, place your signature, sign with your passkey and download the signed copy: Attest runs in the browser and signs with a passkey, so there is no app to install and nothing to print. Signing a PDF you upload yourself uses one of your documents (2 free in total, then $5 a month for 20), while a document someone sends you through Attest is always free: tap Review and sign in their email, set up a passkey with your screen lock, sign once the sender releases it, and download the signed copy from the same link.

By DataHubz · Updated October 12, 2026 · 7 min read

Video: Sign your own documents (1:45), recorded on the real app.

## Why you don't need an app or a printer

Signing on paper means print, sign, scan and send. On an Android phone, Attest replaces all of it with two things you already have.

- **A web browser.** Attest runs in Chrome, with nothing to install.
- **A passkey.** A passkey is a cryptographic key only you control, created for one website and unlocked with your fingerprint, your face or your screen lock (a PIN, pattern or password).

When you sign, your passkey signs a statement that names the exact document, by its SHA-256 hash, and everything you entered on it. A **hash** is a short code calculated from a file's contents: change one character of the file and the hash changes. That is what makes the signature yours and ties it to this version of the document. Attest never sees your passkey's secret.

## How passkeys work on Android

Passkeys are part of Android and Chrome. This is how they work there, according to Google:

- **Which phones.** Android 9 or later, with a screen lock turned on.
- **Where your passkey is saved.** Chrome saves passkeys in Google Password Manager, where they are "securely backed up and synced across your Android devices" signed in to the same Google Account. On Android 14 or later, you can choose another password manager as your passkey provider in your phone's settings.
- **What unlocks it.** Your screen lock, or your fingerprint or face if you have set them up: "Your biometric data is stored on your device and isn't shared with Google." On a phone there is no separate password manager PIN: "On Android, Google Password Manager uses your device's screen lock to access your saved passwords and passkeys." Attest receives the signature your passkey makes, never your fingerprint or face.

## Before you start

- **The PDF on your phone.** Download it from the email first. Google says you can usually find your files in the Files app; some phones have a file app from their manufacturer instead.
- **A PDF of up to 8 MB**, the document you want to sign.
- **Your email address.** Starting free needs nothing else, not even a credit card.

## Sign a PDF someone emailed you

This is for a document you received outside Attest, such as a quote or a service agreement a client emailed you to sign and send back. The video above records the signing part, from **Sign a document yourself** on, on a computer; on your phone, you tap where it clicks.

1. In Chrome, go to attest.datahubz.com/sign and tap **Start free**.
2. Type your email, tap **Email me a sign-in link**, and open the link Attest sends you.
3. Set up your signing key, once. Open the menu, tap **Security**, then tap **Set up with a passkey**.
4. When your phone asks whether to create a passkey in Google Password Manager, tap **Create** and confirm with your fingerprint, face or screen lock. If you chose another passkey provider, its own prompt appears instead.
5. Save the recovery phrase Attest shows you somewhere safe, such as your password manager. Attest can't recover it for you. Check **I saved my recovery phrase.** and tap **Continue**.
6. Open **Documents** and tap **Sign a document yourself**.
7. Tap **Attach the document to be signed** and choose your PDF. Its file name becomes the title, which you can change.
8. Under Verification, keep **Public certificate**, or choose **Private** so that only you can see the certificate (anyone else who looks it up is told it exists and is private).
9. Tap **Next: place your signature**, then tap the page where you sign. If the document asks for initials or a date, choose **Initials** or **Date signed** and tap the page the same way.
10. Tap **Continue to sign**. Attest opens the signing page.
11. Tap **Open and start signing**. The PDF is decrypted on your phone.
12. Tap your signature field. Type your full name, then pick a style or switch to **Draw** and sign with your finger, and tap **Adopt and sign here**. Tap the date field and it fills in the date.
13. Tap **Sign with your passkey** and confirm with your fingerprint, face or screen lock.
14. Tap **View and download the signed copy**, then **Download signed copy**, and attach the PDF to your reply.

Send the copy once it says "every party signed, sealed and anchored". If it says "anchoring now (preliminary copy)", close it and open it again a little later: on the Free plan the anchor is written within about 10 minutes, and on the Signing plan right after you sign. You can also open it later from **Documents**, with **View the signed copy**.

## Sign a document someone sent you through Attest

When someone sends you a document with Attest, you need no account, no password and no plan, and it costs you nothing. Open the email whose subject starts with "Signature requested" and tap **Review and sign**. The first time, tap **Set up with a passkey**, then **Create**, and confirm with your fingerprint, face or screen lock; with most passkey providers this takes one prompt. Because the document is end-to-end encrypted, the sender's browser then releases it to your new key, and Attest emails you when it's ready. Tap **Open and start signing**, fill in the fields Attest guides you to, and tap **Sign with your passkey**. If you don't want to sign, tap **Decline to sign**: that closes the document for everyone and tells the sender. When every party has signed, tap **View and download the signed copy** at the same link: it opens there for 30 days after completion, and after that by signing in with your email. [How to sign a document someone sent you](https://attest.datahubz.com/how-to/sign-document-sent-to-you) walks through every screen.

## Use your Android phone to sign on a computer

Your phone's passkey also works for a computer that has no passkey of its own. In the computer's browser, choose **Use a phone or tablet** at the passkey prompt, scan the QR code with your phone and confirm on the phone. Google notes that your passkeys remain on your phone when you do this.

## What your signed copy contains

The signed PDF is the same file for every party, and it carries its own proof:

- the signed pages, with every signer's entries and each signature in a **Signed with Attest** stamp (the document's verification code, the signing date and a QR code that opens its certificate), and a seal line at the foot of every page with the same code and the link to verify it
- a certificate of completion, an audit trail of every step up to completion and a "Verify it yourself, without us" page, which explains how to check each step without Attest
- three files attached inside the PDF: the full evidence, the original document exactly as signed and a standalone verifier

Anyone can check it for free at attest.datahubz.com/verify, with no account. The open-source verifier inside the PDF runs in any browser, even without Attest, and checks each signer's passkey signature, the original document, the pages you see and Attest's anchored record on Horizen, a public blockchain. If a filing must keep its original page count, **Pages only** downloads just the document's pages, stamps included. It verifies too.

## Attest or a signature drawn on the PDF

Many PDF apps let you draw your signature on a page with your finger. That places an image of your signature on the page. Nothing in the image ties it to you or to this version of the document.

For a casual form, that may be all you need. When you may have to prove the signature later, to a client, a landlord or a lender, use Attest: the signature comes from your passkey, the signed state is anchored on a public blockchain, and if one byte of the document or of your entries changes, verification fails.

## What it costs

| What you sign on your Android phone         | Cost                                                                             |
| ------------------------------------------- | -------------------------------------------------------------------------------- |
| A document someone sends you through Attest | Free, on any plan. It uses none of your documents                                |
| A PDF you upload and sign yourself          | One of your documents: 2 free in total, then the Signing plan, $5 a month for 20 |
| A document you send to other people         | One of your documents, the same way                                              |

The people who sign never pay, and paid plans can be cancelled any time.

## Questions people ask

Do I need to install an app to sign a PDF on Android?

No. Attest runs in Chrome, or another browser that supports passkeys, with nothing to install. You sign with a passkey, which your phone unlocks with your fingerprint, your face or your screen lock.

Does Attest get my fingerprint or face?

No. Your fingerprint or face only unlocks the passkey on your phone, and Google says your biometric data is stored on your device and isn't shared with Google. The passkey signs on your phone, and Attest receives the signature, never the passkey's secret.

Which Android phones can sign with a passkey?

Google says passkeys are supported on Android 9 or later, with a screen lock turned on. Chrome saves them in Google Password Manager, and on Android 14 or later you can choose another passkey provider in your phone's settings.

Is signing my own PDF free?

Your first 2 documents are free, in total. A PDF you upload and sign yourself uses one of them, because it creates a document in your account. After that, the Signing plan is $5 a month for 20 documents. Signing a document someone sends you through Attest is always free.

What if I change phones?

Google says passkeys in Google Password Manager are synced across your Android devices signed in to the same Google Account, so your passkey can come with you. If you set up your key with a recovery phrase, you can also unlock it on any device with that phrase; Attest can't recover the phrase for you. Then add a passkey on that device from the Security page: adding one takes a passkey you already have or your recovery phrase, and Attest emails you whenever a passkey is added.

How do I send the signed PDF back?

Open the signed copy, tap Download signed copy, and attach the PDF to your email reply. Whoever receives it can verify it for free: dropping the PDF on attest.datahubz.com/verify checks the file itself, and the code on its Signed with Attest stamp opens the agreement's certificate.

## Sources

1. [Manage passkeys in Chrome (Android phone and tablet)](https://support.google.com/chrome/answer/13168025?hl=en&co=GENIE.Platform%3DAndroid), Google, read October 12, 2026
2. [Passkey support on Android and Chrome](https://developers.google.com/identity/passkeys/supported-environments), Google for Developers, read October 12, 2026
3. [Find & delete files on Android](https://support.google.com/android/answer/9110661?hl=en), Google, read October 12, 2026

## Read next

- [How to sign a PDF on your iPhone, no app needed](https://attest.datahubz.com/how-to/sign-pdf-on-iphone)
Sign a PDF on your iPhone in Safari with Face ID: no app to install, nothing to print, and a signed copy anyone can verify. Step by step.
- [How to sign a document sent to you and send it back](https://attest.datahubz.com/how-to/sign-document-sent-to-you)
Sign a document someone sent you, free and with no account: from an Attest signing link, or as a PDF attachment you sign and return with its evidence inside.
- [How to verify that a signed document is genuine](https://attest.datahubz.com/guides/verify-signed-document)
Check who signed, that nothing changed and when. How e-signature services verify documents, and how to check an Attest document free, even without Attest.
- [Document signing](https://attest.datahubz.com/sign)
Electronic signatures with a passkey: no account or password for signers, documents encrypted in the browser, and a signed copy anyone can verify.

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Source: https://attest.datahubz.com/how-to/sign-pdf-on-android