Website Header Checker
Check HTTP security headers for any website — audit HSTS, CSP, X-Frame-Options, and other security headers.
About Website Header Checker
Security headers are HTTP response headers that instruct the browser to apply additional security policies. Missing security headers are one of the most common web security misconfigurations. This tool fetches any URL and grades its security header configuration, showing which recommended headers are present, missing, or misconfigured.
FAQ
Which security headers are most important?
In priority order: 1) Strict-Transport-Security (forces HTTPS) 2) Content-Security-Policy (prevents XSS) 3) X-Frame-Options (prevents clickjacking) 4) X-Content-Type-Options: nosniff 5) Referrer-Policy. These 5 address the most common web security vulnerabilities. Check securityheaders.com for a full graded analysis.