Security Headers Checker

Grade for HSTS, CSP, X-Frame-Options, Referrer-Policy and more

Free Online Tool

Security Headers Checker — Complete Guide & Instructions

Grade the HTTP security headers on any site. Nine checks cover transport security, content security, clickjacking, MIME sniffing, referrer leakage, feature permissions and cross-origin isolation — with a parsed breakdown of the CSP directive set.

How to Use Security Headers Checker

  1. 1 Enter a full URL including https://.
  2. 2 Click Check — response headers are fetched and graded.
  3. 3 See the score, per-header results and parsed CSP directives.

Key Features & Capabilities

  • 0–100 score and A–F grade.
  • Nine security header checks including COOP/COEP/CORP.
  • CSP parsed directive-by-directive.
  • frame-ancestors recognised as an X-Frame-Options alternative.