Response Headers
| Header Name | Header Value |
|---|
Security Headers Analysis
Free HTTP Header Checker
Analyze HTTP response headers for any website
Our free HTTP Header Checker inspects the HTTP response headers returned by any website. Analyze security headers, caching policies, content types, and server configuration. Essential for web developers, security professionals, and SEO specialists who need to audit website configurations, verify security headers, and troubleshoot server responses.
📋 What are HTTP Headers?
HTTP headers are metadata sent between client and server with every HTTP request and response. Response headers contain important information about the server, caching behavior, security policies, content encoding, and more. Properly configured headers are crucial for security, performance, and SEO. Security headers like Content-Security-Policy (CSP), Strict-Transport-Security (HSTS), and X-Frame-Options protect against attacks like XSS, clickjacking, and man-in-the-middle. Caching headers like Cache-Control and ETag optimize performance. And headers like X-Content-Type-Options prevent MIME type sniffing attacks.
🛠️ How to Use the HTTP Header Checker
- 1 Enter the full URL of the website you want to analyze (including https://).
- 2 Click 'Check Headers' to send a HEAD request and retrieve the response headers.
- 3 Review the complete list of response headers with their names and values.
- 4 Check the Security Headers Analysis section for a health check of critical security configuration.
- 5 Use the results to identify missing security headers, verify caching policies, and debug server configuration.
✨ Key Features
Complete Header Inspection
View all HTTP response headers including server type, content encoding, caching directives, CORS configuration, and custom headers.
Security Header Audit
Automatic analysis of critical security headers — Content-Security-Policy, HSTS, X-Frame-Options, and more — with clear present/missing indicators.
Instant Analysis
Fast HEAD request retrieval shows response headers without downloading full page content, providing quick results for any URL.
🎯 Common Use Cases
🔒 Security Auditing
Audit your website's security posture by checking critical headers. Verify that HSTS, CSP, X-Content-Type-Options, X-Frame-Options, and Referrer-Policy are properly configured to protect against common web attacks.
🐛 Server Debugging
Debug server configuration issues by inspecting response headers. Check content types, verify redirect chains, examine CORS headers, and troubleshoot caching policies that may be causing issues.
📈 SEO Analysis
Verify SEO-relevant headers like canonical URLs, caching policies, content encoding (gzip/brotli), and server response codes. Proper headers improve page load speed and search engine crawlability.
📋 Compliance Checks
Verify that your website meets security compliance requirements (PCI-DSS, SOC 2, HIPAA) by checking for mandatory security headers and proper HTTPS configuration.
💡 HTTP Header Best Practices
- Enable Strict-Transport-Security (HSTS) with a minimum max-age of 31536000 (1 year) to enforce HTTPS connections.
- Implement Content-Security-Policy (CSP) to prevent XSS attacks — start with 'default-src self' and gradually add trusted sources.
- Add X-Content-Type-Options: nosniff to prevent browsers from MIME-type sniffing, reducing the risk of drive-by downloads.
- Set X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking attacks by blocking your site from being embedded in iframes.
- Configure Cache-Control headers properly — use 'no-store' for sensitive pages and 'max-age' for static assets.
- Remove or anonymize the Server header to avoid revealing your server software and version to potential attackers.
- Set Referrer-Policy: strict-origin-when-cross-origin to control how much referrer information is shared with other sites.
❓ Frequently Asked Questions
What security headers should every website have?
At minimum: Strict-Transport-Security (HSTS), Content-Security-Policy (CSP), X-Content-Type-Options, X-Frame-Options, and Referrer-Policy. Additionally, Permissions-Policy (formerly Feature-Policy) and X-XSS-Protection provide extra protection layers. These headers protect against XSS, clickjacking, MIME sniffing, and man-in-the-middle attacks.
Why are some headers showing as 'Missing'?
Missing security headers indicate that your server isn't sending those protective headers. This doesn't necessarily mean your site is vulnerable, but adding these headers significantly improves your security posture. Check your server configuration (Apache .htaccess, Nginx config, or application middleware) to add them.
Why might I get CORS errors when checking headers?
CORS restrictions may prevent browser-based tools from reading headers of websites that don't include 'Access-Control-Allow-Origin' in their response. This is a normal security feature. If you need to check headers for such sites, try using command-line tools like curl -I or server-side checking.
What is HSTS and why is it important?
HTTP Strict Transport Security (HSTS) tells browsers to only communicate with your website over HTTPS, even if the user types http:// or clicks an HTTP link. This prevents SSL-stripping attacks and protocol downgrade attacks. After seeing the HSTS header, browsers will automatically convert HTTP requests to HTTPS for the specified max-age duration.
How do HTTP headers affect website performance?
Headers directly impact performance: Cache-Control and ETag headers reduce server load and improve page speed by caching static assets. Content-Encoding (gzip, brotli) headers enable compression, reducing transfer sizes by 60-80%. Connection: keep-alive headers allow persistent connections, reducing latency. Proper header configuration can significantly improve Core Web Vitals scores.