HTTP Header Analyzer

Inspect HTTP response headers, redirects, and security header posture
This free online http header analyzer runs in your browser and is part of our Developer Tools collection.

HTTP Header Analyzer

Fetch response headers, redirects, and security-header posture for a URL.

What this helps with

  • Troubleshoot redirects, status codes, and caching behavior
  • Check HSTS, CSP, X-Frame-Options, and related hardening headers
  • Quickly compare security posture across environments
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Instant In-Browser Execution Runs locally in JavaScript without wait times or server delays.
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100% Privacy & Security Your inputs and files are never stored or logged on remote servers.
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Cross-Device Responsive Fully optimized for mobile smartphones, tablets, and desktop displays.
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100% Free Forever No subscription fees, no signups, and no software installations.

How to Use the Online HTTP Header Analyzer

1 Enter Target URL

Input any website address (e.g. `https://example.com`) to inspect its server response.

2 Execute HTTP Request

Click "Analyze Headers" to issue a secure HEAD/GET request and retrieve HTTP headers.

3 Inspect Status & Redirect Chains

Review the final HTTP status code (200, 301, 302, 404) and trace intermediate redirect hops.

4 Evaluate Security Headers Posture

Inspect your score across critical security headers: HSTS, Content-Security-Policy (CSP), X-Frame-Options, X-Content-Type-Options, and Referrer-Policy.

Frequently Asked Questions

Common questions about using this free online http header analyzer.

What are the most critical HTTP security headers for websites? ▾
1) `Strict-Transport-Security` (HSTS) enforces HTTPS; 2) `Content-Security-Policy` (CSP) prevents XSS; 3) `X-Frame-Options` prevents clickjacking in iframes; 4) `X-Content-Type-Options: nosniff` blocks MIME sniffing; 5) `Referrer-Policy` protects user privacy.
What does an HTTP 301 versus 302 status code indicate? ▾
301 Moved Permanently tells browsers and search engines that the URL has moved permanently, transferring SEO ranking authority. 302 Found represents a temporary redirect and does not pass search link equity.
How does HSTS prevent Man-in-the-Middle (MITM) attacks? ▾
HTTP Strict Transport Security instructs browsers never to connect over unencrypted HTTP, automatically converting all insecure requests to HTTPS before transmitting any data over the network.
Can this analyzer inspect web server caching headers? ▾
Yes. It inspects `Cache-Control`, `ETag`, `Age`, and `Expires` headers to help you optimize static asset caching.

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