Software Alternatives, Accelerators & Startups

PDF-LIB VS KeptPDF

Compare PDF-LIB VS KeptPDF and see what are their differences

PDF-LIB logo PDF-LIB

Create and modify PDF documents in any JavaScript environment

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
  • PDF-LIB Landing page
    Landing page //
    2020-02-13
  • 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.

PDF-LIB

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

PDF-LIB features and specs

  • Ease of Use
    PDF-LIB is designed with simplicity in mind, making it easy for developers to work with PDFs without requiring in-depth knowledge of complex PDF structures.
  • No External Dependencies
    The library is self-contained and doesn't rely on external dependencies, which simplifies integration and reduces potential compatibility issues.
  • Cross-Platform
    PDF-LIB can be used in various environments, including web, Node.js, and server-side applications, providing versatility across platforms.
  • Comprehensive API
    It offers a rich set of features for creating and editing PDF documents, including adding text, images, and drawing graphics.
  • Active Development
    The library is actively maintained, with regular updates and a responsive community that helps improve and expand its functionality.

Possible disadvantages of PDF-LIB

  • Performance Limitations
    Handling very large PDF files or performing complex operations may lead to performance issues, as it's a client-side JavaScript library.
  • Limited Advanced Features
    While adequate for many use cases, PDF-LIB may lack advanced features available in more comprehensive PDF libraries, such as OCR or form-field recognition.
  • Lack of Official Support
    There isn’t dedicated professional support, meaning users rely on community forums and GitHub issues for resolving problems.
  • Browser Compatibility
    Some features might not work consistently across all browsers, requiring additional testing and potentially leading to compatibility considerations.
  • Manual Memory Management
    When working with large documents, developers need to manage memory usage explicitly, as JavaScript can be restrictive in environments with limited resources.

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.

Category Popularity

0-100% (relative to PDF-LIB and KeptPDF)
HTML To PDF
100 100%
0% 0
PDF Readers And Editors
0 0%
100% 100
PDF Tools
82 82%
18% 18
Tool
100 100%
0% 0

Questions & Answers

As answered by people managing PDF-LIB 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

Share your experience with using PDF-LIB and KeptPDF. For example, how are they different and which one is better?
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Social recommendations and mentions

Based on our record, PDF-LIB seems to be more popular. It has been mentiond 27 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.

PDF-LIB mentions (27)

  • pdf-lib is silently deleting characters from your users' data
    I generate invoices in a Node serverless function with pdf-lib. It is a good library. It also quietly destroyed a client's company name, threw nothing, logged nothing, and produced a PDF that opened perfectly. - Source: dev.to / 3 days ago
  • I Built a PDF Toolkit That Runs 100% in the Browser — No Server, No Uploads
    Pdfcevir does everything in the browser using pdf-lib and pdf.js. No file ever leaves your device. There's no backend processing the PDF — the JavaScript running in your tab does all the work. - Source: dev.to / about 2 months ago
  • PNG to PDF without losing transparency: what most converters get wrong
    Pdf-lib creates and edits PDFs in pure JavaScript — in the browser, no server. It can embed PNGs with their alpha channel:. - Source: dev.to / 2 months ago
  • I Built a Free Sticker Maker Because Every Other One Hid the Export
    No server round-trip. I render the sheet to a canvas, encode it as a JPEG, and embed it into a PDF with pdf-lib:. - Source: dev.to / 3 months ago
  • I Built 16 Free Dev Tools That Never Touch Your Data — Here's How
    PDF Tools: Uses pdf-lib which runs entirely in the browser. Merge, split, compress, rotate, and watermark — all client-side. - Source: dev.to / 3 months ago
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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 PDF-LIB and KeptPDF, you can also consider the following products

HTML PDF API - Easily generate PDF documents from HTML code with our powerful API

Smallpdf - PDF document management and conversion suite

HTML2PDF.fr - HTML2PDF is a HTML to PDF converter that allows the conversion of valid HTML 4.

iLovePDF - Premium online PDF tool set

Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents

Sejda - Split, merge and other powerful PDF tools.