HTML Foundations — Prerequisites for Web Penetration Testing

A complete, beginner-friendly guide to HTML for anyone preparing to learn web penetration testing. It teaches how web pages are built — structure, forms, the DOM, cookies, headers, and DevTools — so that the security topics you study next (XSS, CSRF, injection, clickjacking, and so on) make sense.

This is a foundations book, not a hacking book. It contains no attack payloads. It builds the prerequisite knowledge a tester needs before touching security tooling, and it stresses that you must only ever test systems you own or are explicitly authorized to test.

Contents

Part I — The Web

1. What is HTML?
2. How the Web Works (HTTP & URLs)

Part II — HTML Core 3. Document Structure 4. Elements & Tags 5. Attributes 6. Links & Navigation 7. Images & Media 8. Tables 9. Forms & Inputs

Part III — The Browser 10. The DOM 11. HTML & CSS 12. HTML & JavaScript 13. HTML5 Features

Part IV — Pentest Prep 14. Reading Source Code 15. Using DevTools 16. HTML & HTTP Headers

Audience & level

Absolute beginners with no prior HTML experience. Useful as preparation for tracks such as eJPT, OSCP, PNPT, and bug-bounty work.

A note on responsible use

Practise only on systems you own or on legal, intentionally vulnerable targets (e.g., PortSwigger Web Security Academy, OWASP Juice Shop, DVWA, TryHackMe, Hack The Box). Unauthorized testing is illegal in most jurisdictions.