Software Alternatives, Accelerators & Startups

FBReader VS KeptPDF

Compare FBReader VS KeptPDF and see what are their differences

FBReader logo FBReader

FBReader is an e-book reader for various platforms. Features:

KeptPDF logo KeptPDF

Redact, edit, OCR, and sign PDFs entirely in your browser. The file never leaves your device. Free, no account needed.
Visit Website
  • FBReader Landing page
    Landing page //
    2022-10-22
  • KeptPDF Landing page
    Landing page //
    2026-08-22

KeptPDF is a PDF toolkit that runs entirely in your browser. Nothing uploads: every tool runs on your own device, so the document never touches a server.

What it does:

  • Redaction that auto-detects names, SSNs, phone numbers, addresses, and dates, then removes the underlying text instead of drawing a box over it. Every redacted file gets an audit certificate that anyone can verify.
  • OCR that makes scanned PDFs searchable, with on-device processing.
  • Sign, annotate, compare, organize, split, merge, compress, convert, watermark, Bates numbering, exhibit stamps, and more. About 25 tools in total.
  • A command line version runs the same redaction engine on your own servers for bulk work: scanning bureaus, litigation support teams, and records departments process thousands of PDFs in one pass.

Who it is for: law firms, accounting practices, clinics, and anyone who shares documents they cannot afford to leak.

The core tools are free with no sign-up. Works offline as an installable app.

FBReader

Pricing URL
-
$ Details
-
Release Date
-

KeptPDF

$ Details
freemium $29 / Monthly (Pro, 1 user)
Release Date
2026 May
Startup details
Country
United States
State
Tennessee
Founder(s)
John Whitworth

FBReader features and specs

  • Platform Support
    FBReader is available on multiple platforms including Windows, macOS, Linux, Android, and iOS, making it accessible to a wide range of users.
  • Format Compatibility
    The reader supports a variety of ebook formats like EPUB, MOBI, FB2, HTML, RTF, and plain text, which offers flexibility to readers.
  • Customization
    FBReader allows extensive customization options such as font types, sizes, colors, and background images, letting users personalize their reading experience.
  • Library Management
    The app offers robust library management features including book organization, sorting, and categorization, making it easier to manage large collections.
  • Speed
    FBReader is known for its speed and efficiency in loading books and navigating through them, which provides a smooth reading experience.

Possible disadvantages of FBReader

  • User Interface
    Some users find the user interface to be outdated and less intuitive compared to other modern ebook readers, which can affect usability.
  • Limited Advanced Features
    While FBReader covers basic reading needs, it lacks some advanced features found in other readers, such as annotations, bookmarks synchronization, and cloud storage integration.
  • DRM Support
    The app does not support DRM-protected content, limiting its use with books purchased from certain vendors like Amazon or Google Play.
  • In-App Purchases
    The free version of FBReader has limited features, and users need to make in-app purchases to unlock additional functionalities, which may not be ideal for all.
  • Performance on Older Devices
    Some users have reported performance issues when running FBReader on older or less powerful devices, which can interrupt the reading experience.

KeptPDF features and specs

  • Simple PDF Editing
    KeptPDF offers straightforward tools for editing, merging, splitting, and converting PDF files, making it accessible for users who need quick document management without a steep learning curve.
  • Web-Based Accessibility
    Being a web-based tool, KeptPDF can be accessed from any device with an internet connection, eliminating the need for software installation and allowing use across different operating systems.
  • Multiple File Format Support
    The platform supports conversion between PDF and various other file formats, offering flexibility for users who work with documents in different formats.
  • No Installation Required
    Since it operates in a browser, users can save storage space on their devices and avoid compatibility issues that sometimes arise with desktop software installations.
  • Quick Processing
    KeptPDF is designed to process PDF tasks efficiently, allowing users to complete common document tasks like compression or conversion in a relatively short amount of time.

Analysis of FBReader

Overall verdict

  • FBReader is generally considered a good option for users looking for a reliable and flexible e-book reader. It provides a smooth reading experience and is often appreciated for its cross-platform availability and customization options.

Why this product is good

  • FBReader is a popular e-book reader known for its versatility and support for multiple file formats, including EPUB, MOBI, FB2, and more. It allows users to customize their reading experience by adjusting fonts, colors, and layouts. The application is lightweight, available across various platforms, and often praised for its easy-to-use interface.

Recommended for

    FBReader is recommended for readers who value customization in their reading experience and need support for various e-book formats. It's ideal for those who read on multiple devices and platforms, as it offers sync features and wide compatibility.

FBReader videos

Review FBReader on Linux Ubuntu

More videos:

  • Review - FBReader Android Review
  • Review - FBReader - Best eBook Reader App [Android/iOS] #03

KeptPDF videos

No KeptPDF videos yet. You could help us improve this page by suggesting one.

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Category Popularity

0-100% (relative to FBReader and KeptPDF)
eBook Reader
100 100%
0% 0
PDF
0 0%
100% 100
Ebooks
100 100%
0% 0
PDF Readers And Editors
79 79%
21% 21

Questions & Answers

As answered by people managing FBReader and KeptPDF.

What makes your product unique?

KeptPDF's answer:

KeptPDF runs entirely in your browser. Your file, and the text inside it, never leaves your device. Not to an AI, not even to us. You can open your browser's network tab and watch: the document bytes never go out.

Most online PDF tools upload your file to a server first, and some "AI redaction" services quietly send your document text to a third-party model. That is the exact risk people are trying to avoid when they redact something.

KeptPDF also does true redaction. The text is removed from the file, not covered with a black box you can copy out later. Every redaction produces a verification certificate you can share with the file.

Why should a person choose your product over its competitors?

KeptPDF's answer:

Three reasons.

Privacy you can verify, not just a promise. Processing happens locally in the browser, so there is no upload step to trust. We do send anonymous usage counts for quota, and we say so plainly, but never your document.

Real redaction with proof. Removed text is permanently gone, and you get a certificate showing the file was checked for leftover extractable text. Automated detection cannot catch everything, so a final human review is still your job, and the tool says that too.

It works on a phone. Most PDF suites assume a desktop. KeptPDF was built and used on a phone first, so redacting a document while you are standing in a hallway actually works.

How would you describe the primary audience of your product?

KeptPDF's answer:

Anyone who has to hand a document to someone else and needs the sensitive parts gone first.

In practice that is solo attorneys and small law firms, accountants and tax preparers, healthcare and records staff handling requests, HR teams, and individuals dealing with their own medical, legal, or financial paperwork.

The common thread is not an industry. It is a person who cannot upload a confidential file to a random website, and who does not have an enterprise IT budget to solve it.

What's the story behind your product?

KeptPDF's answer:

A family member got seriously ill. We spent most days at the hospital, and straight answers were hard to come by, so we leaned on AI tools to make sense of the records, notes, and lab results.

But you cannot paste a medical record into an AI chat. You have to strip the names, the ID numbers, the diagnoses first. And almost every tool we found either wanted to upload the whole file to a server, or "auto-redacted" by sending the document text to an online AI. That was the exact thing we were trying to avoid.

Most of this was happening on a phone, at a bedside. So I built the tool I needed: redaction that runs on the device, works on mobile, and never sends the file anywhere. That turned into KeptPDF, which is now a full PDF suite with over 20 tools, all local-first.

Which are the primary technologies used for building your product?

KeptPDF's answer:

The app is plain JavaScript with no front-end framework, which keeps it fast and keeps the code auditable.

PDF work happens in the browser using pdf.js for rendering and pdf-lib for writing. Text recognition uses Tesseract running as WebAssembly. Password and encryption handling uses a WebAssembly build of qpdf. It is a Progressive Web App, so it installs and works offline.

The thin server side is Node on Vercel, with Postgres for accounts, Stripe for billing, and Resend for email. None of those ever see a document.

Who are some of the biggest customers of your product?

KeptPDF's answer:

KeptPDF is early and independent, and we do not publish customer names. The product is privacy-first by design: we never see your documents, and we do not track who our users are or what they work on. Publishing a client list would sit badly next to that.

The user base today is mostly solo attorneys, small firms, accountants, and individuals handling their own records.

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare FBReader and KeptPDF

FBReader Reviews

8 Best eBook Readers for Linux
FBReader is a lightweight, multi-platform ebook reader, free but not open-source, supporting various formats like ePub, fb2, mobi, rtf, html etc. It includes access to popular network libraries from where you can download ebooks for free or buy one.
Source: itsfoss.com
10 of the Best Ebook Readers for Windows, macOS, and Mobile
The Favorite Book Reader (FBReader) is a free app that used to be open source. As such, it used to be available for a multitude of devices but now caters to iOS and Android users. Thereโ€™s also a beta version in development for the Onyx reader.

KeptPDF Reviews

We have no reviews of KeptPDF yet.
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Social recommendations and mentions

Based on our record, FBReader seems to be more popular. It has been mentiond 10 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

FBReader mentions (10)

  • What is a good ebook reader for Linux?
    I use fbreader, it's probably in your disto's repository or you can get in from fbreader.org. Source: over 3 years ago
  • Best ebook app that also allows for reader?
    I've been using FBreader for years, and it can use the built in Android TTS. https://fbreader.org/. Source: almost 4 years ago
  • 3x new books added to the Pirate Library Mirror (+24TB, 3.8M books)
    Based on what's on ZLibrary, various formats, though principally PDF, ePub, Mobi (Kindle), DJVU (similar to PDF), FB2, and a few others. Most ebook readers (with the exception of Amazon's own Kindle reader) can read virtually all of these, some with extensions. E.g., FB Reader , PocketBook Reader , Onyx's Neoreader (BOOX) ... No... - Source: Hacker News / almost 4 years ago
  • FOSS or privacy conscious ebook reading app (Mac/iOS)
    I came across FBReader which looks great in principal, but it uses a Google Drive account to sync with no other options. Also it's no longer OSS from 2015 (which wouldn't have been a deal breaker for me). Source: about 4 years ago
  • I need a good Software to read epub
    I use FBreader on android and PC. It's insanely customizable. I sometimes use it it double-page layout, 'though I haven't tried comics. Source: over 4 years ago
View more

KeptPDF mentions (0)

We have not tracked any mentions of KeptPDF yet. Tracking of KeptPDF recommendations started around Aug 2026.

What are some alternatives?

When comparing FBReader and KeptPDF, you can also consider the following products

calibre - Ebook manager, viewer & converter

Smallpdf - PDF document management and conversion suite

Amazon Kindle - Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and...

iLovePDF - Premium online PDF tool set

Cool Reader - Fast and small cross-platform eBook reader for desktops and handheld devices

Sejda - Split, merge and other powerful PDF tools.