Here are some of the best online courses for web security:

• OWASP Web Security Academy: This free course from the Open Web Application Security Project (OWASP) covers the fundamentals of web security. It includes modules on topics such as SQL injection, cross-site scripting (XSS), and session management.
• The Complete Ethical Hacking Course: This course from Udemy teaches you how to hack websites and web applications. It covers topics such as finding vulnerabilities, exploiting vulnerabilities, and covering your tracks.
• Web Application Security with Kali Linux: This course from Pluralsight teaches you how to use Kali Linux, a penetration testing distribution of Linux, to secure web applications. It covers topics such as scanning for vulnerabilities, exploiting vulnerabilities, and reporting on vulnerabilities.
• Cybersecurity for Web Developers: This course from Coursera teaches you how to secure web applications from the perspective of a web developer. It covers topics such as input validation, output encoding, and session management.
• Certified Ethical Hacker (CEH): This certification from EC-Council is one of the most popular certifications in the field of ethical hacking. It covers a wide range of topics related to web security, including vulnerability assessment, penetration testing, and social engineering.

These are just a few of the many great online courses available for web security. With so many options available, you’re sure to find a course that’s right for you.