How to sign a PDF on Android

Every answer to this question starts by telling you to install something, and Google’s own summary at the top of the results is no exception: open it in Acrobat Reader, or in Drive. That is not lazy advice. It is the honest consequence of a real gap. An iPhone carries one marking tool inside the operating system, reachable from wherever a document happens to be, and an Android phone has nothing sitting in that position. No share-sheet entry puts ink on a page.

What the install-an-app answer skips is that something changed in the last two years, and it is worth knowing before you download anything. Two apps already on your phone will draw on a PDF. Neither is quite the answer you were after, and the reason has nothing to do with the drawing — it is where the marked copy ends up.

Why the phone has no equivalent of Markup

The piece of Android that understands PDFs is a component for developers rather than a feature for you. It paints pages onto the screen; writing anything back onto them has, for most of the platform’s life, been something each app had to build for itself. So there is no shared signing surface for apps to borrow, no menu that appears in every document, and consequently no single answer to give somebody. The answer is always the name of an app, because an app is the only place the capability has ever lived.

That is a genuine structural difference and not an oversight anyone is about to fix from your side of the screen. It also means the question worth asking is not which app but where does my document go, which turns out to sort the options cleanly.

The two Google apps that already draw on a page

The Drive app has done this since 2023, on anything running Android 6 or newer. Open a PDF that lives in Drive, look for the annotation control in the lower corner of the preview, and you get a pen, a highlighter and an eraser, usable with a finger or a stylus. When you are finished you may write over the original or keep it and save a marked copy alongside. For drawing a signature this is entirely adequate — a finger on glass is closer to a pen on paper than a mouse will ever be.

The condition is in the first sentence. The document has to be in Drive, which means that if it arrived as an email attachment or a download it has to be put there first. The marking happens on the phone; the document was already on Google’s servers before you started.

Files by Google looks like it closes that hole, and this is the part most guides have not caught up with. Since its PDF viewer was rebuilt at the end of 2024 it opens a document sitting in your own Downloads folder and offers the same set of tools behind an edit control. Local file, local drawing, no upload — right up to the moment you save. Google’s own instructions are unambiguous about what happens then: the copy you saved goes to your Google Drive, and what stays on the device is the original, still unmarked.

Read that twice, because it is the whole shape of signing on Android. The ink is local. The saving is not. You end up with an unsigned document on your phone and a signed one in the cloud, which is the exact inverse of what somebody signing a lease in a hurry assumes they just did.

Galaxy phones have a route that stays put

If your phone is a Samsung, you have something the rest of Android does not. Samsung Notes imports a PDF as a note, lets you write on it with the S Pen or a finger, and exports the result back out as a PDF. Nothing leaves the handset at any point in that sequence, and on a device with a pen it is the most natural signing experience on any phone, full stop.

It is worth naming precisely because it is easy to miss: the app is a notebook, so nobody looking for a signing tool thinks to open it. The import lives behind the new-note button rather than anywhere labeled PDF.

The routes, and where each one leaves your document

Adobe deserves its row read fairly. Fill & Sign was folded into the free Acrobat Reader app when the standalone one was retired, and placing a drawn or typed signature does not cost money. What it costs is the install, the sign-in the app keeps asking for, and a permanent resident on a phone’s storage for a job you may do twice a year.

What “upload your PDF” actually means, and what it does not

The e-signature services are not villains and it is not useful to pretend they are. They are established businesses with contracts and security teams, and the odds of a specific lease being read by a human at one of them are effectively nil.

The accurate objection is smaller and more durable: an upload is another place the document exists. Every copy has a retention period you did not choose, sits under a jurisdiction you did not pick, and belongs to a company the other party to your agreement never agreed to involve. A lease names your address. An employment offer names your salary. A medical consent form names your condition. None of those documents are yours alone, and consent to hand them around was not yours alone to give either.

That is a reason to prefer a route without an upload when one exists — not a reason for alarm when it does not. If you want to test any tool’s claim rather than believe it, checking whether a web tool really runs locally shows you how to watch the network yourself; it takes about a minute and works on a phone.

Signing in the browser, which the phone happens to be good at

The tab you are reading this in can do the job. Signing a PDF here opens the document from your own storage, and the drawing surface is the thing a touchscreen is better at than any laptop: you sign with a finger at roughly the size you sign on paper, and the drawing is cropped tight around your strokes, so a small signature in the corner of the box does not arrive on the page as a speck.

Placement is a tap rather than a drag, which matters more on a phone than anywhere else — you put your finger where the signature goes and it lands centered there, then nudge it if it needs nudging. There is a width control, a way to repeat the same mark on every page for documents that demand one per sheet, and the finished file is shown to you before you save it rather than after. Nothing installs, no storage permission is requested, and the document is never sent anywhere. If your phone is a Galaxy, Samsung Notes is a fine alternative and this is the one that also works on the borrowed laptop.

A practical note if the document arrived in several pieces, which contracts often do: merging the PDFs first gives you one file to sign once instead of three, and if the file came locked, the password has to come off before anything can be written into it — what those two kinds of PDF password actually are explains which one you are looking at.

Does a drawn signature count?

For everyday agreements, yes, and it has been that way for a long time — a mark you placed deliberately on a document is what electronic signature law is built around, and none of the routes above produce anything stronger or weaker than the others in that respect. What none of them produce is a cryptographic signature with a certificate behind it, which is a different technology that some counterparties specifically require. The signing tool’s own page sets out where that line falls and how to tell which side of it you are on before you send the file rather than after it bounces.

And if you are reading this on a Chromebook

Then you are in better shape than the phone users, and this is worth stating plainly because plenty of pages tell Chromebook owners they are stuck. ChromeOS has a built-in answer. The Gallery app, which is what opens a PDF when you double-click it, includes a signature feature: you draw once with a finger, a stylus or the trackpad, then place the result on the page, and it fills form fields too. The file stays on the device and the save is a normal save.

Two caveats. Google’s own note beside that feature says it is there for convenience and carries no verification — the same limit as every route on this page. And a managed school or work Chromebook held back on an older release may not have the annotation tools at all, which is the case where a browser tab is still the shortest way through.