Software Alternatives, Accelerators & Startups

PDFTron VS KeptPDF

Compare PDFTron VS KeptPDF and see what are their differences

PDFTron logo PDFTron

PDF components and tools.

KeptPDF logo KeptPDF

Redact, edit, OCR, and sign PDFs entirely in your browser. The file never leaves your device. Free, no account needed.
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  • PDFTron Landing page
    Landing page //
    2023-10-09
  • 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.

KeptPDF

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

PDFTron features and specs

  • Comprehensive Feature Set
    PDFTron offers a wide range of features, including PDF viewing, editing, annotation, conversion, and form filling, which makes it suitable for diverse use cases.
  • Cross-Platform Support
    PDFTron provides robust support for multiple platforms, including Windows, macOS, Android, iOS, and web, allowing for versatile application development.
  • High Performance
    The software is known for its high-performance rendering and processing capabilities, which ensures smooth handling of large and complex PDF documents.
  • Active Development and Updates
    PDFTron is continuously updated with new features and improvements, ensuring developers have access to modern tools and capabilities.
  • Customizability
    PDFTron provides extensive APIs and customization options, allowing developers to tailor the solution to specific needs and use cases.

Possible disadvantages of PDFTron

  • Cost
    PDFTron's licensing costs can be high compared to some other PDF solutions, which might be a barrier for small businesses or individual developers.
  • Complexity
    Given its wide array of features, PDFTron can be complex to implement and may require a steep learning curve for developers unfamiliar with the platform.
  • Overhead for Simple Use Cases
    For applications that require only basic PDF functionality, PDFTron's comprehensive feature set may be more than necessary, leading to increased implementation complexity.
  • Documentation
    Some users have reported that while the documentation is extensive, it can sometimes be difficult to navigate or lacks depth in certain areas.

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.

PDFTron videos

PDFTron - Year in Review 2020

More videos:

  • Demo - PDFTron SDK Demo -5 minute overview- View PDF, MS Office, images, customization, redaction, editing

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 PDFTron and KeptPDF)
Business & Commerce
100 100%
0% 0
PDF
0 0%
100% 100
File Management
100 100%
0% 0
PDF Readers And Editors
0 0%
100% 100

Questions & Answers

As answered by people managing PDFTron 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 PDFTron and KeptPDF

PDFTron Reviews

PDFTron vs. ComPDFKit | Compare the Best PDFTron Alternative
The PDFTron SDK is a robust and professional PDF library designed to meet the needs of demanding and diverse applications. It is developed in-house and offers high-quality rendering capabilities that can accurately and reliably handle digital content of any size and complexity. With PDFTron, developers can bring PDF, CAD, and MS Office functionalities to their software...
Source: www.compdf.com
2024 Best JavaScript PDF Viewer
PDFTron WebViewer (also known as Apryse WebViewer) is a JavaScript PDF & Document SDK that lets you add advanced document processing as part of any web application. Itโ€™s also a commercially licensed library that includes a deep feature set to let users create PDFs, add annotations, collaborate on documents, insert bookmarks and digital signatures, and more.
Source: www.compdf.com

KeptPDF Reviews

We have no reviews of KeptPDF yet.
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What are some alternatives?

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

Parascript - Parascript is an AI-powered Intelligent Document Processing software that makes it possible for you to automate the extraction of data from any type of document, whether itโ€™s a contract, a form, or an invoice.

Smallpdf - PDF document management and conversion suite

Kofax TotalAgility - Kofax TotalAgility Platform transforms and simplifies information-rich customer interactions via the worldโ€™s first unified digital transformation platform.

iLovePDF - Premium online PDF tool set

Workfusion Intelligent Automation Cloud - Intelligent Automation Cloud is a secure, unified platform for AI-powered RPA and process analytics that your team can install quickly and scale easily.

Sejda - Split, merge and other powerful PDF tools.