In our journey to become penetration testers, we learn about powerful tools and potent techniques. There’s a natural, exciting urge to want to try them out. But let me state the single most important rule in our field, a rule that has no exceptions: You must never, ever test on a system you do not own or have explicit, written permission to attack.

Practicing your skills on a random website, even “just to see what happens,” is illegal, unethical, and will end your career before it has a chance to begin. It’s the equivalent of a medical student deciding to practice surgery on a stranger they meet on the street.

So, how do you go from theory to real, hands-on skill? You train in a dojo. In cybersecurity, our dojos are dedicated, purpose-built penetration testing labs and platforms. These are safe, legal environments designed to be hacked. They are the gyms where you will build your skills, the proving grounds where you will forge your expertise.

This guide will introduce you to the best and most respected platforms in the industry. For anyone in Nepal starting their journey, these resources are your key to becoming a true professional.

1. TryHackMe (THM)

• Best For: Absolute Beginners and Guided Learning.
• What it is: TryHackMe is a browser-based, online platform that gamifies the learning process. It features thousands of “rooms,” each focused on a specific security topic. A room typically includes instructional material followed by a real, vulnerable virtual machine that you can attack directly from your browser or by connecting via a VPN.
• Why I Recommend It: This is the perfect starting point. If you are new to the field, start here. The “learning paths” (like the Jr Penetration Tester path) provide a complete, structured curriculum that takes you from zero to hero. The step-by-step guidance is invaluable for building foundational confidence.
• Cost: It has an excellent free tier that is more than enough to get you started. The premium subscription (around $10-14 USD/month) unlocks all rooms and is one of the best investments you can make in your education.

2. Hack The Box (HTB)

• Best For: Intermediate Learners and Real-World Challenges.
• What it is: Hack The Box is the next step up in difficulty. It’s less about guided learning and more about real-world challenges. You are typically given just an IP address for a vulnerable machine (“box”) and your goal is to hack it. The platform features a massive library of retired machines, as well as more complex scenarios like “Fortresses” and “Endgames” that simulate a full corporate network.
• Why I Recommend It: HTB is where you prove your skills. The machines are famous for being creative and challenging, closely mimicking real-world scenarios. It is considered essential practice for anyone preparing for the tough OSCP certification. Writing detailed “write-ups” of how you solved HTB machines is one of the best ways to build a portfolio for your CV.
• Cost: There is a free tier with a set of rotating active machines. The VIP subscription (around $15-20 USD/month) gives you access to the entire library of retired machines and is highly recommended for serious learners.

3. OWASP Juice Shop

• Best For: Learning Web Application Hacking.
• What it is: The OWASP Juice Shop is a modern, sophisticated, and intentionally insecure web application. It is not an online platform, but rather software that you run on your own machine (or in the cloud). It is packed with dozens of vulnerabilities from the OWASP Top 10.
• Why I Recommend It: If you want to specialize in web application security, this is your primary training ground. It teaches you how to find and exploit real-world flaws like SQL Injection, Cross-Site Scripting (XSS), and Broken Access Control in a safe environment. It also has a built-in scoreboard that tracks your progress and provides hints, making it a fun, gamified experience.
• Cost: It is completely free and open-source.

4. VulnHub

• Best For: Building Your Offline Lab and Boot2Root Practice.
• What it is: VulnHub is not a platform you log into, but a massive community-contributed repository of vulnerable virtual machines. You download the VM image file and run it in your own local lab using software like VirtualBox or VMware.
• Why I Recommend It: This platform teaches you a critical skill: how to set up and manage your own testing environment. The machines are almost all “boot2root” challenges, meaning you start with no access and your goal is to fully compromise the machine and become the ‘root’ user. This is excellent practice for developing a full penetration testing methodology.
• Cost: Completely free.

5. PentesterLab

• Best For: Structured Web and Code Injection Exercises.
• What it is: PentesterLab provides hundreds of small, isolated exercises, with each one focused on a single, specific vulnerability. Instead of a full machine with multiple steps, you might get a single webpage with one type of XSS flaw, or a specific API endpoint with an SQL injection vulnerability.
• Why I Recommend It: This platform is perfect for “deep-diving.” When you want to truly master a specific type of attack, PentesterLab allows you to practice that technique dozens of times in slightly different variations. Their exercises on web vulnerabilities are some of the best in the world.
• Cost: It has a selection of free exercises. The Pro subscription unlocks the full library and is a valuable resource for serious web testers.

Conclusion: Practice Smart, Practice Safe

There is no excuse for practicing your skills illegally. The platforms and resources available today are affordable, incredibly effective, and will teach you far more than you could ever learn by randomly poking at live websites.

Your career in cybersecurity is built on a foundation of trust and ethics. Start the right way. Build your lab, sign up for these platforms, and join the global community of ethical hackers who are dedicated to learning and improving their skills in a safe and responsible way. The skills you build here will open doors to a real career. The mistakes you make on other people’s systems will close them forever.