HTTP Headers Analyzer

Inspect HTTP response headers, security policies, and caching settings for any URL

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Why Analyze HTTP Headers?

HTTP response headers control how browsers interpret and render web content. They enforce security policies, define caching behavior, declare content types, and much more. Analyzing headers helps developers, security engineers, and site owners identify misconfigurations, security vulnerabilities, and performance opportunities before they become problems.

Who Needs an HTTP Headers Analyzer?

Security Engineers & Penetration Testers

  • • Identify missing security headers like CSP, HSTS, and X-Frame-Options
  • • Detect server software version disclosures in Server headers
  • • Validate security header configurations against best practices

Web Developers & DevOps

  • • Debug caching issues with Cache-Control and ETag headers
  • • Verify CORS headers are correctly set for API endpoints
  • • Confirm CDN headers like X-Cache and CF-Cache-Status

Website Owners & SEO Specialists

  • • Ensure pages return correct HTTP status codes (200, 301, etc.)
  • • Verify X-Robots-Tag for crawl control outside of HTML meta tags
  • • Check Content-Type headers are set correctly for all resources

HTTP Headers Analyzer Information

What are HTTP response headers?

HTTP response headers are metadata sent by a web server along with the response body. They convey information such as content type, caching rules, security policies, server software, and more. Browsers and clients use these headers to properly handle the response.

Why should I analyze HTTP headers?

Analyzing HTTP headers helps you identify security vulnerabilities (missing security headers), diagnose caching issues, verify content types, check server software versions, and ensure your website follows best practices for performance and security.

What is the Content-Security-Policy header?

Content-Security-Policy (CSP) restricts which resources (scripts, styles, images) a browser can load for your page. A well-configured CSP prevents cross-site scripting (XSS) attacks by whitelisting trusted sources.

What does Strict-Transport-Security (HSTS) do?

HSTS tells browsers to always use HTTPS when connecting to your site, even if the user types http://. This prevents SSL stripping attacks and protocol downgrade attacks. Once set, browsers enforce HTTPS for the duration specified in max-age.

How does Cache-Control affect performance?

Cache-Control directives tell browsers and CDNs how long to cache a resource. Values like max-age=31536000 cache content for a year (ideal for versioned assets), while no-cache forces revalidation on every request. Proper caching dramatically improves page load speed.

What is X-Frame-Options used for?

X-Frame-Options prevents your site from being embedded in an iframe on another domain. This protects against clickjacking attacks where an attacker overlays invisible frames to trick users into clicking malicious elements. Modern sites should use the CSP frame-ancestors directive instead.

Pro Tips

  • • Always include Strict-Transport-Security to enforce HTTPS and prevent downgrade attacks.
  • • Set X-Content-Type-Options: nosniff to prevent MIME-type sniffing vulnerabilities.
  • • Use Cache-Control: immutable for versioned static assets to maximize CDN cache efficiency.
  • • Remove Server and X-Powered-By headers in production to avoid disclosing technology stack.
  • • Implement a Content-Security-Policy to significantly reduce XSS attack surface.
  • • Add Referrer-Policy: strict-origin-when-cross-origin to control how referrer info is shared.