📋 HTTP Security Headers Checker

Analyze HTTP response headers and get a security score for any website.

What Are HTTP Security Headers?

HTTP security headers are directives sent by web servers that instruct browsers how to handle content. They provide an additional layer of security against common web vulnerabilities.

Essential Security Headers

  • Strict-Transport-Security (HSTS): Forces HTTPS connections Forces HTTPS connections
  • Content-Security-Policy (CSP): Prevents XSS and injection attacks Prevents XSS and injection attacks
  • X-Frame-Options: Protects against clickjacking Protects against clickjacking
  • X-Content-Type-Options: Prevents MIME sniffing Prevents MIME sniffing
  • Referrer-Policy: Controls referrer information Controls referrer information
  • Permissions-Policy: Restricts browser features Restricts browser features

Understanding Our Security Score

We grade your headers from A+ to F based on the presence and configuration of critical security headers. An A+ grade means all recommended headers are properly configured.

HTTP Security Headers Checker analyzes security-related response headers protecting against XSS, clickjacking, MIME sniffing, and protocol downgrade attacks.

Key Facts

  • Only 10% of top 1M sites have proper CSP
  • HSTS preloading protects from first visit
  • X-Frame-Options prevents 90%+ of clickjacking
  • Proper headers prevent 80% of common web attacks

Frequently Asked Questions

What is Content-Security-Policy?

CSP controls which resources browsers can load. The most powerful defense against XSS attacks.

What is HSTS?

Forces browsers to always use HTTPS, preventing protocol downgrade attacks and cookie hijacking.

Why low security grade?

Usually missing CSP, HSTS, X-Frame-Options, X-Content-Type-Options, or Referrer-Policy headers.

How to add security headers?

In Apache .htaccess, Nginx server block, or CDN dashboard (Cloudflare, Vercel, Netlify).