A rigorous Security Headers Checker is an indispensable auditing tool for webmasters, DevSecOps engineers, and digital agencies seeking to protect websites against cross-site scripting (XSS), clickjacking, and packet sniffing attacks. HTTP response headers instruct web browsers on how to handle site content and enforce strict cryptographic security boundaries.

HTTP Security Headers & SSL Grade Scanner

Scan any website to audit its HTTP response headers (HSTS, CSP, X-Frame-Options) and calculate an instant security rating with copy-paste remediation rules.

Why You Must Audit With a Security Headers Checker

While installing an SSL/TLS certificate encrypts data in transit between the client and server, an SSL certificate alone does not defend against client-side code injection or framing vulnerabilities. When web browsers fetch HTML pages without protective headers, they default to legacy behaviors that leave users vulnerable to malicious third-party scripts.

By running our Security Headers Checker, you receive an instantaneous audit grade (from A+ down to F), highlighting missing directives alongside production-ready configuration snippets for Apache, LiteSpeed, and Nginx web servers.

The 6 Essential Security Headers Every Website Needs

  • Strict-Transport-Security (HSTS): Enforces modern HTTPS connections and prevents SSL-stripping attacks. Setting max-age=31536000; includeSubDomains; preload qualifies your site for browser HSTS preload lists.
  • Content-Security-Policy (CSP): The ultimate defense against Cross-Site Scripting (XSS). Restricts the specific origins from which scripts, stylesheets, fonts, and images can be executed.
  • X-Frame-Options: Defends against Clickjacking attacks by prohibiting malicious websites from embedding your pages inside hidden iframes. Configure as DENY or SAMEORIGIN.
  • X-Content-Type-Options: Prevents MIME-type sniffing by setting nosniff, forcing browsers to honor the declared content type.
  • Referrer-Policy: Governs how much URL path data is transmitted in HTTP Referer headers when users click outbound links. Use strict-origin-when-cross-origin.
  • Permissions-Policy: Disables unauthorized browser APIs (e.g., geolocation, microphone, and webcam access) across embedded third-party scripts.

How to Implement A+ Security Headers on Your Server

To fix missing headers detected by our scanner, copy and paste the generated directives directly into your server configuration files:

For Apache / LiteSpeed (.htaccess):

<IfModule mod_headers.c>
  Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
  Header always set X-Frame-Options "SAMEORIGIN"
  Header always set X-Content-Type-Options "nosniff"
  Header always set Referrer-Policy "strict-origin-when-cross-origin"
  Header always set Permissions-Policy "geolocation=(), microphone=(), camera=()"
</IfModule>

After updating your web server, verify that your compliance policies are up to date using our Cookie Policy Generator and test your network routing with our IP & Domain Intelligence Inspector. For official header guidelines, consult Mozilla MDN Web Docs and the OWASP Secure Headers Project.