HTTP Security Headers Checker

HTTP security headers are special response headers that your web server sends to the browser along with your page content. They instruct the browser on how to behave when handling your site's data -- for example, whether to allow embedding in iframes, which scripts can run, whether to enforce HTTPS, and more. They serve as a critical second line of defense against common web attacks like cross-site scripting (XSS), clickjacking, MIME-type sniffing, and protocol downgrade attacks.

Content-Security-Policy (CSP) and Strict-Transport-Security (HSTS) are the two most critical headers. CSP prevents cross-site scripting attacks by controlling exactly which resources the browser is allowed to load on your page. HSTS forces browsers to always use HTTPS, preventing man-in-the-middle attacks and cookie hijacking. Together they account for nearly half of the overall security header score. X-Frame-Options (clickjacking protection) and X-Content-Type-Options (MIME sniffing prevention) are also high priority.

There are several ways to add security headers. You can configure them at the server level via Apache .htaccess rules or Nginx config blocks. Many CDN providers like Cloudflare and Fastly also let you set headers in their dashboard. For WordPress sites, the easiest approach is a security plugin like GuardPress Pro that adds all missing headers automatically with one click -- no server access or manual configuration required.

Yes, this HTTP security headers checker is completely free to use with no limits on the number of scans. No login, account, or credit card is required. Simply enter any URL and get instant results with a detailed grade, per-header analysis, and actionable recommendations to improve your security posture.