Security Headers Checker
Guide
Security Headers Checker
Paste HTTP response headers to instantly analyze your site’s security posture. Checks all critical security headers, assigns an overall grade from A+ to F, and provides actionable fix recommendations with server configuration examples.
How to Use
Paste your HTTP response headers (key: value format, one per line) into the input field. The tool analyzes eight critical security headers and displays a color-coded report with an overall security grade, per-header status, and fix recommendations.
Features
- 8 Security Headers Analyzed – CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, COOP, and COEP
- Security Grading – Overall grade from A+ to F based on header presence and configuration quality
- CSP Validation – Syntax checking and directive analysis for Content-Security-Policy headers
- HSTS Preload Check – Verifies preload eligibility (includeSubDomains, max-age requirements)
- Fix Recommendations – Actionable suggestions with nginx, Apache, and Express configuration examples
- Color-Coded Results – Green for properly configured, yellow for warnings, red for missing or misconfigured
- Header Explanations – Clear descriptions of what each header does and why it matters
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