Free online security headers audit. Check CSP, HSTS, and more with A-F grades.
Free online security headers audit. Check CSP, HSTS, and more with A-F grades. Enter a website URL (including https://) you want to audit. Click "Check Headers" to fetch and analyze the site's HTTP security headers. Review the A-F letter grade for each security header with detailed feedback. Check the overall security score and fix recommendations for failing headers. Fetches response headers through our API and applies practical configuration checks. Grades are heuristics, not an official OWASP or Mozilla Observatory score or a security certification.