Helmet.js
Helmet.js is a Node.js middleware library for Express.js applications that helps secure web applications by setting various HTTP headers. It provides a simple way to configure security-related headers like Content Security Policy (CSP), X-Frame-Options, and X-XSS-Protection to protect against common web vulnerabilities. By default, it sets 11 security headers, making it a popular choice for enhancing the security posture of Express-based web apps.
Developers should use Helmet.js when building Express.js applications to easily implement security best practices and protect against attacks like cross-site scripting (XSS), clickjacking, and other common web threats. It is particularly useful for production deployments where security headers are essential for compliance and reducing attack surfaces, and it simplifies what would otherwise require manual header configuration.