Hackr.gg

Hackr.gg is a learning platform for offensive web security that runs entirely in the browser with no virtual machine or setup. It offers 85 modules of short lessons on real attacks, including SQL injection, cross-site scripting, broken authentication, API flaws and server-side request forgery, and each lesson ends with a quick check.

Many lessons include inline labs where you try the attack yourself, such as a login bypass exercise. Topics span web fundamentals, injection attacks, XSS, authentication and API security, recon and OSINT, a hacker toolkit covering tools like sqlmap, ffuf, curl, Burp Suite and hashcat, network and systems hacking, and LLM and AI security with prompt injection. The site cites 628 lessons, 1,340 quiz questions and 144 practice exercises, plus a roadmap, academy and certification section.

Twelve modules are free without a credit card, and the remaining modules sit on paid plans described on the pricing page. It suits beginners and developers who want to learn how web applications get attacked and defended.