What are HTTP Response Headers?

HTTP response headers are metadata parameters sent by a web server to a browser in reply to an HTTP request, containing details like server type, date, encoding, content type, and security policies.

Why are Security Headers important?

Security headers (like CSP, HSTS, X-Frame-Options) tell web browsers how to handle site content safely, protecting users against cross-site scripting (XSS), clickjacking, and man-in-the-middle attacks.

What is HSTS (Strict-Transport-Security)?

HSTS is a security header that forces web browsers to interact with a website only using secure HTTPS connections, preventing secure cookies from being leaked over unencrypted HTTP pathways.

How does the tool calculate the security grade?

The tool checks for six primary security headers: CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. Your grade (A+ to F) depends on how many of these are active.

Free HTTP Headers Checker - Analyse Website Security Headers

Security Header Rating

Security Headers Checklist

Strict-Transport-Security ✓ Secure

Content-Security-Policy ✓ Secure

X-Frame-Options ✓ Secure

X-Content-Type-Options ✓ Secure

Referrer-Policy ✓ Secure

Permissions-Policy ✓ Secure

HTTP response headers parameters

HTTP/1.1 200 OK
Date: Thu, 28 May 2026 19:24:00 GMT
Server: Nginx
Content-Type: text/html; charset=UTF-8
Content-Length: 4890
Strict-Transport-Security: max-age=31536000; includeSubDomains
Content-Security-Policy: default-src 'self' https:; script-src 'self' 'unsafe-inline';
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: geolocation=(), camera=()

How to Verify Web Server Response Headers

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1. Search Domain

Enter any website domain URL address in the inspector input bar (e.g. google.com).

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2. Verify Checklist

Analyze security policy mappings. Verify clickjacking and XSS script defenses live.

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3. Audit Server Grades

Check compliance grades (A+ to F). Check raw headers values like Server and Date logs.

Security Compliance Features

🚀 Smart Compliance checklists

Integrated checker loops CSP, HSTS, and XSS headers, compiling active security metrics.

🛡️ Multi Niche Server Presets

Includes robust preset fallback datasets (Nginx, Cloudflare, Apache) to analyze mock structures offline.

🔒 Safe sandboxed parsing

All evaluations calculate locally inside browser volatile threads, securing confidential domains.

Frequently Asked Questions

Why do browsers block raw header checks via JS? +

Browsers enforce strict CORS (Cross-Origin Resource Sharing) security. Direct javascript ajax calls to foreign domains block headers to prevent cookie and authorization token leakage. Our tool leverages proxy fallbacks to bypass this.

What represents an 'A' grade in security headers? +

An 'A' or 'A+' grade is awarded when all primary security parameters (HSTS, CSP, X-Frame-Options, X-Content-Type-Options, and Referrer-Policies) are configured with strict, non-permissive values.

How does Content-Security-Policy (CSP) help? +

CSP restricts the locations from which web browsers can load external scripts, media, styles, and frames. This significantly limits the capability of attackers to inject malicious tracking scripts (XSS).

What is X-Frame-Options? +

This header instructs browsers whether your site can be embedded inside `

HTTP Response Headers Checker

How to Verify Web Server Response Headers

Security Compliance Features

Frequently Asked Questions