PDF reader for Android — top free apps reviewed

Seven free options, at a glance

Permission profile — the matrix the Play Store does not show

Android permissions are the right lens for comparing PDF readers. The matrix below captures what each app needs to function, plus what it requests by default beyond that.

Detailed take on each reader

Google Drive — the no-install default

Google Drive ships pre-installed on most Android phones and includes a competent PDF viewer for files saved to Drive or downloaded locally. The reader supports basic highlighting and comments and integrates with the Android Storage Access Framework.¹ For purely reading-and-occasional-comment workflows, this is the right default — no install, no permission negotiation, and tight integration with the Drive cloud account most Android users already have.

Xodo — the polished free annotation experience

Xodo (now owned by Apryse) is the most polished free Android PDF reader for active annotation in 2026. The free tier includes tabbed UI, drawing tools, highlights, text annotations, signatures, basic form fill, and cloud-storage integration (Drive, Dropbox, OneDrive, Box). No core feature is locked behind a paywall, and the advertising posture is minimal. For users who annotate dozens of PDFs a week on a phone or tablet, Xodo is the easy recommendation.

Adobe Acrobat Reader — for Adobe-pipelined workflows

Adobe Reader on Android handles Adobe-pipelined documents most faithfully, includes Liquid Mode for re-flowing PDFs to mobile screens, and integrates with Adobe Sign for request-a-signature workflows. The trade-off is aggressive push toward Adobe Document Cloud and the paid Premium tier in onboarding. For corporate users whose counterparties send Adobe-Sign-pipelined documents, Adobe Reader is worth installing; for general use, it is overkill on a phone.

Foxit PDF Reader Mobile — cross-platform parity

Foxit's pitch is the same reading and annotation experience across Windows, macOS, Linux, iOS, and Android. If you already use Foxit on the desktop, the mobile app is the natural pair — annotations and signatures travel cleanly between platforms. For users without an existing Foxit habit, Xodo is typically the better free choice.

Librera Reader — for many ebook formats

Librera is a multi-format reader (PDF, ePub, MOBI, FB2, DjVu, CBZ, RTF, TXT) that handles PDF well alongside the rest. The free Play Store tier shows ads; the F-Droid "libre" build strips them out. Annotation is limited; this is primarily a reading app. For users with mixed ebook+PDF libraries, Librera is convenient because one app handles everything.

Document Viewer (MuPDF-based) — the privacy choice

Document Viewer (previously known as MuPDF Viewer) is an open-source Android PDF reader built on the MuPDF engine.² It contains no telemetry, no advertising, no Internet permission, and no account requirements. The UI is austere — pan, zoom, page navigation, full-text search, and that is roughly it. For users on de-Googled Android (LineageOS, GrapheneOS, /e/OS) or anyone who wants a tracker-free reader, Document Viewer is the right install. Available on F-Droid.

ScoutMyTool in Chrome / Firefox mobile

For editing tasks Android readers handle poorly — signing, watermarking, page numbers, merging, splitting, compressing, form fill — ScoutMyTool's browser tools work in Chrome, Firefox, Brave, or Samsung Internet on Android with no install. Each tool runs client-side in the browser tab; nothing transits a server. Useful as the "second tool" alongside whichever reader you choose for the read-and-annotate phase.

Which one to install — decision tree

1. Only ever read PDFs occasionally? Drive's built-in viewer is enough. Do not install anything.
2. Annotate PDFs regularly on the phone? Install Xodo. Best free annotation experience.
3. Receive Adobe-pipelined corporate documents? Install Adobe Reader alongside Drive (not instead).
4. Already use Foxit on desktop? Install Foxit Mobile for parity.
5. Privacy is your top concern? Install Document Viewer from F-Droid. No trackers, no Internet permission, open source.
6. Mixed PDF + ebook reading? Install Librera (libre F-Droid build for ad-free).
7. Need to actively edit / sign / watermark a PDF? Bookmark ScoutMyTool in your mobile browser.

Related ScoutMyTool tools and articles

• All free PDF tools — browser-based toolbox that works on Android Chrome/Firefox.
• Sign PDF — sign without installing a desktop or mobile app.
• Add Watermark — confidentiality or "draft" stamps.
• Merge PDF — combine PDFs in the browser.
• Compress PDF — shrink a PDF before sending via email or chat.
• PDF Form Fill — fill AcroForm fields without an app.
• How to e-sign a PDF on iPhone — sister piece for the iOS side.
• Best PDF reader for Mac — sister piece for macOS.
• Best PDF reader for Windows — sister piece for Windows.

Frequently asked questions

Does Android come with a built-in PDF reader?

Functionally yes. Most Android phones come with Google Drive pre-installed, and Drive includes a serviceable PDF viewer for files saved to Drive or downloaded locally. The reader supports basic highlighting and comments, and integrates with the Android Storage Access Framework. The limits become visible if you annotate heavily or work with complex forms — Drive's viewer is a quick-look tool, not a full PDF reader. For those cases, install one of the alternatives below.

Which Android PDF reader is the most privacy-friendly?

Document Viewer (MuPDF-based), available on F-Droid under the GPL. It contains no telemetry, no advertising, no tracker code, and no account requirements — you can install it on a device that has never seen Google Play Services and it works perfectly. Librera Reader has a libre build on F-Droid too, which is similar in posture. For users who want both privacy and rich annotation, Xodo is the next-best choice — it is closed source but does not collect identifying telemetry by default, and the annotation feature set is the most complete in the free tier.

Is Adobe Acrobat Reader worth installing on a phone?

Only if your workflow involves Adobe-pipelined documents — review packets sent from Acrobat Pro on a desktop, fillable forms exported by Adobe Sign, or corporate documents that ask for Adobe-branded comments. For everyday reading and basic annotation, Adobe Reader is overkill on a phone — it is heavier, more aggressive about cloud sync to Adobe Document Cloud, and pushes the paid Premium tier in onboarding. Xodo or the built-in Drive viewer are usually better choices for a phone.

What is "Liquid Mode" and is it actually useful?

Liquid Mode is an Adobe Acrobat Reader feature that re-flows PDF content for mobile screens — text wraps to screen width, font sizes increase, and the original page layout is abandoned. For long-form text PDFs (academic papers, ebooks) on a small phone screen, Liquid Mode dramatically improves readability. For PDFs where the page layout matters (forms, charts, multi-column briefs, anything with absolute positioning), Liquid Mode produces garbled output. It is genuinely useful for one category of PDFs and counter-productive for others — try it and switch back to standard view if the output looks wrong.

Can I sign PDFs on my Android phone for free?

Yes. Several paths. Adobe Reader has a built-in Fill & Sign feature on the free tier — draw a signature with your finger or stylus, place it on the page, save. Xodo has the same flow. The most privacy-friendly path is ScoutMyTool's Sign PDF tool in Chrome or Firefox mobile — runs entirely in your browser tab, no upload, no app install, and works on any Android phone with a recent browser. All three produce legally binding signatures under the US ESIGN Act and the EU eIDAS framework for simple electronic signatures.

Can I edit a PDF on Android, not just annotate it?

Annotation (highlight, draw, text overlay, signature) is well-supported. True editing (modifying the original page content) is limited on every Android reader because the underlying PDF model is hard to edit on a touch UI. For real edits — merging files, splitting into sections, compressing for email, adding page numbers, filling AcroForm fields — open ScoutMyTool in Chrome or Firefox mobile. Each tool runs in the browser tab without uploading, and the workflows are designed for touch input.

What permissions should an Android PDF reader actually need?

A bare-minimum reader needs only Storage / Files access (to read the PDF). Anything beyond that — Internet, Camera, Contacts, Location — is the app asking for permissions that are not required for PDF viewing. The Internet permission is necessary for cloud-storage integration (Drive, Dropbox) but is also how analytics and ads phone home. If you want maximum privacy, install a F-Droid reader (Document Viewer or libre Librera) that does not request Internet at all. For mainstream Play Store apps, review the listed permissions before installing — anything claiming Contacts, SMS, or Location is overreach.