Best PDF reader apps in 2021

best pdf reader
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The best PDF reader apps for Android and iPhone don't just let you open files on your smartphone (though they excel at that). Instead, you get lot of navigation, annotation and cloud storage capabilities in the very apps, putting a document management tool at your fingertips.

PDFs are light, portable and can support a variety of document styles, from text-heavy manuals to highly image-based documents such as ebooks and comics. Form-fillable documents can also be used as official forms. So having a good PDF reader at hand gives you access to all of these documents and more. 

If you're looking for extensive editing tools, check out our picks for best PDF editors (including the top free PDF editors). But if you just want to skim PDFs on your mobile device, here are the best PDF reader apps we've seen for Android and iOS.

Best PDF reader apps for Android and iOS

1. Adobe Acrobat Reader (Android, iOS: Free)

best pdf reader: Adobe Acrobat Reader

(Image credit: Adobe)

The biggest thing that Adobe Acrobat Reader has going for it is that everything just works smoothly, supporting form-fillable and DRM and password-protected PDFs while offering a variety of view modes, from your classic vertical scroll to a two page facing view that looks great in landscape mode. 

Adobe Acrobat Reader includes text reflow, contextual search, bookmarks and hyperlink support, as well as annotation and electronic signature support. Users who sign up to a free Adobe Document Cloud account can share and sync documents online, with features like PDF editing and creation available as in-app purchases or through subscription.

2. Foxit Mobile PDF (Android, iOS: Free)

Best PDF Reader: Foxit

(Image credit: Foxit Software)

The mobile version of the popular desktop tool, Foxit Mobile PDF is another one of the best PDF reader apps for your mobile device. 

On the display end, Foxit handles normal and password protected PDFs, with support for document and user bookmarks. Annotation options let you highlight, underline or strike through text. You also can add sticky notes text boxes, or even draw freehand on the document. 

Text reflow allows you to read comfortably even on a small smartphone screen. Cloud support lets you upload and download PDFs from popular storage providers. 

Foxit has also introduced a new ConnectedPDF feature for collaborative work, annotations, comments and edits on a team's files.

3. PDF Viewer Pro (Android, iOS: Free)

best pdf reader: PDF Viewer Pro

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PDF Viewer Pro is one of the best PDF readers that you can download and work with for free. But the mobile app is also designed to offer a variety of power user features for anyone looking to spend on premium subscriptions. 

Free users can take PDF Viewer Pro and open up PDFs stored locally or in the cloud, as well as apply annotations and basic document edits. Pay up for a subscription — three months costs $6.99 while a year goes for $19.99 — and you can access features like combining documents or interpolating pages, image annotations, an interface-free presentation mode, and interface customization.

4. Xodo PDF Reader (Android, iOS: Free)

best pdf reader: Xodo

(Image credit: Xodo Technologies)

Xodo PDF Reader might not have the big name recall of Acrobat Reader or Foxit, but it still offers a nice multi-platform reader app that includes a variety of reading modes along with organization and cloud storage tools. You also get productivity extras like annotations and electronic signatures. 

Users can open and edit their local PDF files; access PDFs from their Dropbox, Google Drive and OneDrive; or they can use the proprietary Xodo Connect platform to share and annotate PDFs over a web browser. 

That said, the mobile reader would be improved with a better design and layout, as features like the menu bars can use up a large amount of screen space and obscure pages, making Xodo somewhat clunky to use.

5. Soda PDF Merge (Android, iOS: Free)

Best PDF readers soda Pdf merge

(Image credit: Lulu Software)

What happens when you've got a number of documents on your phone that you want to turn into a single PDF? That's where Soda PDF Merge comes in. The app can merge contract details, photos, and just about any document you want into a single file for review.

Soda PDF Merge supports Word, PPT, Excel, JPG and other file formats. You can also scan documents with your phone's camera. Merging documents is dead simple, and you're even able to compress the size of the file to save on the space it occupies on your phone.

6. Google Play Books (Android, iOS: Free)

best pdf reader: Google Play Books

(Image credit: Google)

Google Play Books is another best PDF reader worth considering for its cloud storage functions. You can upload your own PDF & EPUB files into your Play Books library for cross-device ease of reading, though if you do most of your PDF reading away from a wireless signal, that may be an issue. 

In addition to cloud storage features, you can also access Play Books' marketplace, as well as customize the reader view for ease of use. Text highlighting, a built-in dictionary, and map search give you features to play with, and cross-device syncing lets you save your reading position across devices.

7. Markup - Annotation Expert (iOS: Free)

best pdf reader: Markup

(Image credit: Kdan Mobile Software)

Markup - Annotation Expert is Kdan's beefier, professional-oriented version of its PDF viewer and annotation software for iOS devices. As the name suggests, the app includes markup and annotation tools for PDF documents and a Web highlighter through an in-app browser, as well as support for audio notes and digital signatures. 

The cloud portion of Markup supports a variety of storage and backup options, such as Dropbox, Google Drive, or Kdan Cloud. Limitations on the free version such as number of files stored are removed on the $5.99/month Pro version and a $9.99/month paid subscription to Kdan's Creativity 365 suite of tools includes more premium features.

  • Download Markup: iOS

8. iAnnotate (iOS: $9.99)

best pdf reader: iannotate

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iAnnotate is a slick PDF reader and annotator that comes with a lot of nice features and customizations for your PDF reading and editing convenience. 

Users can open up PDF files in this best PDF reader, search for terms and keywords and navigate through bookmarks or a continuous scroll view mode. The real hallmark of the program is the powerful set of annotation features that allows you to add notes, draw, highlight, underline and strike through; you can also add digital signatures. 

A Web capture mode lets you convert web pages into PDFs for annotation and easy sharing. Tabbed browsing means you can have multiple documents opened for quickly flipping through your books and docs. PDFs can be flattened, imported to various cloud services, or emailed to recipients.

  • Download iAnnotate: iOS

9. MuPDF (Android, iOS: Free)

best pdf reader: MuPDF

(Image credit: Artifex Software)

MuPDF is a lightweight, open source document viewer that handles PDF, XPS, CBZ and ePUB documents with equal aplomb, though the focus is clearly on PDF files. 

MuPDF features support for PDF 1.7, text reflow, progressive rendering for large documents. It can also handle basic interactive features such as text search and extraction, hyperlinks, annotations, form-filling and electronic signatures. 

If you don't need fancy extras like cloud integration or advanced editing features, consider giving this best PDF reader a shot.

10. AnDoc (Android: Free)

best pdf reader: Andoc

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Where many PDF readers provide a wide variety of features, AnDoc PDF & DJVU Reader instead aims for a minimalist, interface, hiding most of its options and navigation behind the settings button. 

This is a bit of a pro and con — while the reading experience is clutter free, accessing outlines, search tools, and bookmarks requires you to fire up the settings menu. 

That said, the app does include a surprising degree of back end options, allowing users to tweak performance and rendering settings, set the appearance of hyperlinked text and more. If you don't need annotation features and are looking for a clutter-free reading view, consider AnDoc.

11. WPS Office (Android, iOS: Free)

best pdf readers: WPS Office

(Image credit: Kingston Office Software)

From extreme minimalism to something a bit more all-in-one, we go to WPS Office, a multipurpose mobile office suite that handles documents, spreadsheets, and PDFs with equal aplomb. 

WPS's PDF viewer is serviceable, allowing users to add and view bookmarks, jump to page numbers, text search, view annotations to a PDF file, and access PDFs from cloud storage. It's not as loaded with PDF-centric features as other viewers, but it's general office suite features make it a good addition to your app drawer if you're looking for a free mobile document editor that also reads PDFs well.

12. PDF Expert (iOS: $9.99)

best pdf reader: PDFExpert

(Image credit: Readle)

On the iOS front, Readdle's PDF Expert line of apps is among the most impressive premium PDF tools available for mobile users. PDF Expert can open the full spectrum of PDF files, including password protected and form-fillable documents. 

The app also supports a variety of other document formats stored locally or in the cloud. Drawing tools, highlighting and other text annotation tools provide the means to mark up documents, while text search, PDF links and other navigation tools make getting to where you want a snap.

  • Download PDF Expert: iOS

13. PDFpen 6 (iOS: $6.99)

best pdf reader: PDFPen

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PDFpen 6 is another one of the best PDF readers and editors for iOS users. The mobile app allows users to display PDF files, as well as edit, annotate, apply proofmarks, images and signatures. These features make it extremely easy to handle form-fillable files and other important documents. 

Users can "flatten" documents for easier compatibility, set document passwords and save or load documents across a wide variety of cloud services, such as iCloud, Dropbox, Evernote and Google Drive. 

It may cost more than some of the other free PDF readers, but PDFpen 6 does provide a thorough suite of tools for reading and editing PDFs on your iOS device, and it's well worth it if you're a professional who needs to deal with PDFs on the go.

  • Download PDFpen 6: iOS

14. GoodReader PDF Editor and Viewer (iOS: $5.99)

best pdf reader: GoodReader

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A powerful PDF reader for iOS devices, GoodReader offers a variety of annotation, navigation, and file management tools. Search tools, text reflow and other navigation tools allow you to easily get to where you need in a doc, while text and freehand annotation tools and digital signature let you easily make your mark. An included file manager lets you handle documents on your device, with support for uploading and downloading to cloud storage. 

GoodReader continues to add new features, such as support for page management, auto-syncing of files and text-to-speech.

  • Download GoodReader PDF Editor and Viewer: iOS

15. Kybook 3 (iOS: Free)

best pdf reader: kybook 3

(Image credit: Konstantin Bukeev)

As an ebook reader — it's one of the best ebook reader apps, in our opinion —KyBook 3 takes a generalist approach, supporting a variety of formats. One of those happens to be PDF, making KyBook a good choice if you're looking for the best PDF reader, too. 

KyBook throws in a ton of features such as cloud storage support, text to speech, search, bookmarks, and notes, but the app does suffer compared to other readers due to its more generalist approach. PDF pages don't quite load as smoothly as a more focused PDF reader, but KyBook does do the job well enough, with customizable page turn modes, support for landscape and two-page facing modes, and a magnifying loupe. 

It's worth considering if you regularly consume DRM-free PDFs alongside other ebook and audiobooks. In-app purchases unlock features like DjVu support, synchronization, and PDF Reflow. 

  • Download KyBook 3: iOS
John Corpuz
John Corpuz flip-flopped between computer science and creative writing courses in school. As a contributor to Tom's Guide he's found a happy middle ground writing about apps, mobile gaming and other geekery.