CSP Header Builder

A Content-Security-Policy (CSP) header is a security mechanism that controls which resources a web page can load, helping protect against cross-site scripting (XSS), clickjacking, and data injection attacks. By defining trusted sources for scripts, stylesheets, images, fonts, and other content types, CSP dramatically reduces the attack surface of your web application. Modern web security best practices emphasize CSP as a critical layer of defense, especially when combined with HTTPS and other protective measures.

This tool makes building a CSP header intuitive by letting you toggle each directive on or off, customize source lists for different content types, and instantly see the resulting header syntax ready to copy. You can add specific domains, wildcard patterns, or use CSP keywords like 'self', 'none', 'unsafe-inline', and 'strict-dynamic' to precisely control resource loading. The generator handles syntax validation and escaping, ensuring your header is properly formatted before deployment to your web server.

CSP headers are essential for web developers, security engineers, and teams managing content delivery networks or third-party integrations. Whether you're hardening a public-facing website, protecting user data in a single-page application, or enforcing strict security policies across a microservices architecture, this tool simplifies the often complex process of CSP configuration. Level 3 CSP support is becoming standard in modern browsers, making this an increasingly important security investment.