HTTP Headers Checker

HTTP headers are metadata fields that provide additional information about HTTP requests and responses. They contain critical data about content type, caching policies, security measures, server information, and encoding. Understanding HTTP headers is essential for web development, SEO optimization, security assessment, and troubleshooting website issues. They help browsers and servers communicate effectively and implement proper security measures.

Essential security headers include Content-Security-Policy (CSP) to prevent XSS attacks, X-Frame-Options to prevent clickjacking, Strict-Transport-Security (HSTS) for HTTPS enforcement, X-Content-Type-Options to prevent MIME sniffing, X-XSS-Protection for XSS filtering, and Referrer-Policy to control referrer information. These headers form a crucial defense layer against common web vulnerabilities and should be properly configured on all websites.

Yes, our HTTP headers checker tool is completely free to use with no restrictions, registration requirements, or hidden fees. You can check unlimited URLs and access all features without any cost. The tool is web-based and works directly in your browser, making it accessible whenever you need to analyze HTTP headers for security, SEO, or debugging purposes.

HTTP headers significantly impact SEO and performance through caching directives, compression settings, and content-type specifications. Proper cache-control headers improve page load speeds, content-encoding headers enable compression for faster downloads, and content-type headers ensure correct content interpretation. Security headers also indirectly affect SEO by building user trust and preventing security issues that could harm search rankings.

Yes, our HTTP headers checker can analyze headers from any publicly accessible website or web service. It works with HTTP and HTTPS URLs, APIs, CDNs, and various web servers. The tool can handle different response types including HTML pages, images, APIs, and other web resources. However, it cannot access URLs behind authentication or private networks due to browser security restrictions.

Missing security headers indicate potential vulnerabilities in your website's security configuration. Without proper headers like CSP, your site may be vulnerable to XSS attacks; missing X-Frame-Options can allow clickjacking; absent HSTS headers may permit downgrade attacks. While not all headers are required for every site, implementing appropriate security headers is a best practice that significantly improves your website's security posture.

Cache-Control headers determine how browsers and CDNs should cache your content. Common directives include max-age (cache duration), no-cache (always validate), no-store (never cache), and public/private (caching scope). ETag headers provide cache validation, while Last-Modified headers indicate content freshness. Proper caching headers improve website performance by reducing server load and speeding up page loads for returning visitors.

Absolutely! Our HTTP headers checker is fully responsive and works perfectly on mobile devices, tablets, and desktop computers. The interface adapts to different screen sizes while maintaining full functionality. You can check HTTP headers on any device with a web browser, making it convenient for on-the-go analysis and troubleshooting.

Server headers reveal valuable information about the web server software, version numbers, supported technologies, and configuration details. You can identify whether a site uses Apache, Nginx, IIS, or other servers, discover content management systems, check for CDN usage, and understand the technology stack. This information is useful for competitive analysis, security assessment, and understanding how websites are built and configured.

Headers show as missing when the web server doesn't send them in the response. This could be due to server configuration, security practices (hiding server information), or simply because the headers aren't necessary for that particular resource. Not all headers are required for every website, but security-critical headers should generally be present. Missing headers might indicate configuration opportunities or security improvements.