HTML Encoding Fundamentals for Web Security

Web applications are constantly exposed to user-generated input, making them vulnerable to malicious exploits if not handled correctly. Understanding how to safely render this data is one of the most critical defense mechanisms in modern web development. In this text-only course, you will learn how to prevent Cross-Site Scripting (XSS) and code injection by mastering the principles of HTML encoding. You will transition from understanding basic character representation to implementing secure data-rendering strategies across different web contexts. What you will learn: • Understand the core concepts of HTML encoding, character sets, and browser parsing. • Identify the differences between HTML entity, attribute, and JavaScript encoding. • Prevent Cross-Site Scripting (XSS) vulnerabilities by safely handling user input. • Learn how modern web frameworks handle auto-escaping and where manual encoding is still required. • Explore complementary security measures like Content Security Policy (CSP) to build multi-layered defenses. • Practice identifying vulnerable code patterns and applying correct encoding techniques through written exercises. The course begins with foundational definitions of encoding, character sets, and browser parsing behaviors before moving into practical scenarios, analyzing vulnerable code snippets, and learning how to apply context-aware encoding. This course is designed for beginner web developers and security enthusiasts, with no prior security experience required. Start reading today to build safer, more resilient web applications.