PentesterLab
TryHackMe
Hack The Box
VulnHub
PwnTillDawn Online Battlefield
HackThisSite
CodeRed by EC-Council
LetsDefend
KeptPDF
Smallpdf
iLovePDF
Sejda
Adobe Acrobat DC
CompilaPDF
FoxyUtils Online PDF Tools
OnDevicePDF
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:
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.
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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.
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.
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.
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.
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.
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.
Based on our record, PentesterLab seems to be more popular. It has been mentiond 17 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.
Learning Websites: PortSwigger Web Security Academy - Free, comprehensive web security training. I recommend PortSwigger Academy if you are starting out. Bugcrowd University - Free educational resources for bug bounty hunters. Bugcrowd also provides a platform for the Vulnerability Disclosure Program (VDP) and Bug Bounty Programs (BBP). It is a good place to start your bug bounty hunting by creating an account... - Source: dev.to / over 1 year ago
For pentesting, look at the below: - https://portswigger.net/web-security - https://pentesterlab.com/ - https://www.hackthebox.com/. Source: over 3 years ago
These codes can be useful in different situations. A good site to test out different types of attacks and recon is: http://pentesterlab.com (mind it has a premium subscription plan but u can use it free). Source: almost 4 years ago
I’d strongly recommend PentesterLab (https://pentesterlab.com/) as they have very real world examples that should be helpful to you. I have no affiliation with this company, just a fan. Source: about 4 years ago
Https://www.hackthebox.com/ has free retired boxes to punch and it isn't expensive if you want to access new ones. It is security orientated, but you still have to understand the basics and there are plenty of walk throughs. Proving Ground is another. https://www.offensive-security.com/labs/ pentersterlabs has a free tier https://pentesterlab.com/ https://www.udemy.com/ has free courses for about anything If... Source: about 4 years ago
TryHackMe - TryHackMe is an online platform for learning and teaching cyber security, all through your browser.
Smallpdf - PDF document management and conversion suite
Hack The Box - An online platform to test and advance your skills in penetration testing and cyber security.
iLovePDF - Premium online PDF tool set
VulnHub - VulnHub provides materials allowing anyone to gain practical hands-on experience with digital security, computer applications and network administration tasks.
Sejda - Split, merge and other powerful PDF tools.