Software Alternatives & Startups

PDF Annotator VS KeptPDF

Compare PDF Annotator VS KeptPDF and see what are their differences

PDF Annotator

Comment and edit PDF. Add text, highlights, drawings, images. Insert, delete & merge pages. Handwritten PDF annotations. 2M+ downloads! FREE trial.

Rating
0 reviews
KeptPDF

Redact, edit, OCR, and sign PDFs entirely in your browser. The file never leaves your device. Free, no account needed.

Rating
0 reviews
Pricing
Freemium $29 / Monthly (Pro, 1 user)

Which is more popular?

PDF Tools popularity
81% vs 19%
alternatives listed
101 vs 26

Base details

Website, pricing, platforms and company facts side by side.

PDF Annotator
KeptPDF
Website pdfannotator.com keptpdf.com
Pricing —
Freemium $29 / Monthly (Pro, 1 user) Official pricing
Company — Startup from the United States · 2026
Listed in

About PDF Annotator and KeptPDF

In their own words, as submitted to SaaSHub.

PDF Annotator
KeptPDF

No description of PDF Annotator yet.

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...

Read more about KeptPDF

Features and specs

What each product offers, as listed by its team.

PDF Annotator 5 features
KeptPDF 5 features
  • Comprehensive Annotation Tools
    PDF Annotator offers a wide variety of annotation tools such as text, drawing, and highlighting options, providing users with flexibility in how they mark up documents.
  • User-Friendly Interface
    The software boasts an intuitive and easy-to-navigate interface, making it accessible for users of varying technical skill levels.
  • Versatile File Support
    PDF Annotator can handle large PDF files and supports various file formats, making it a versatile tool for managing and annotating documents.
  • Integration with Digital Handwriting
    It supports digital handwriting, which is useful for users who prefer using styluses or touchscreens for annotation.
  • Searchable Annotations
    Annotations made in PDF Annotator are searchable, enabling users to quickly find notes and comments made within the document.

Possible disadvantages

  • Windows-Only
    PDF Annotator is only available for Windows operating systems, limiting its accessibility to users on Mac or Linux platforms.
  • Cost Factor
    While PDF Annotator offers robust features, it is a paid software, which could be a limitation for users seeking free annotation tools.
  • Limited Advanced Editing Features
    The software focuses primarily on annotation and lacks some advanced editing features found in other PDF editing suites.
  • Performance with Very Large Files
    Although it handles large PDFs, extremely large or complex files can sometimes result in slowed performance.
  • Occasional Bugs
    Some users have reported occasional bugs or crashes, particularly when handling complex or graphic-intensive documents.
  • 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.

Videos

Walkthroughs and reviews on video.

PDF Annotator 3 videos + Add
KeptPDF 0 videos + Add

PDF Annotator Review For Teachers

More videos

  • - PDF Annotator webinar Add comments, corrections, signatures, highlighting, even photos and drawings.
  • - PDF Annotator Review For Teachers Registration

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

Category popularity

How often each product is chosen within a category, 0–100% relative to the other.

Score bands 0–20 21–40 41–50 51–60 61–100
PDF Annotator
KeptPDF
81% 81%
19% 19%
100% 100%
0% 0%
0% 0%
PDF
100% 100%
100% 100%
0% 0%

Questions & Answers

As answered by people managing PDF Annotator 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 and articles

External articles and on-site reviews we used to compare the two products.

PDF Annotator no reviews yet
KeptPDF no reviews yet
  • Top 5 PDF Annotators free
    www.geekersoft.com · Sep 2022

    Have you ever needed to annotate PDF files in your daily work and life? If you've ever annotated a PDF file, you know how messy and painful this process can be. PDF Annotator is a tool developed to solve this problem,...

We have no reviews of KeptPDF yet. Be the first one to post

Alternatives to PDF Annotator and KeptPDF

When comparing PDF Annotator and KeptPDF, you can also consider the following products.