Free Online HTTP Headers Checker

What are HTTP Headers?

HTTP headers are a core part of HTTP requests and responses in web communication. They are key-value pairs that transmit additional information between the client (e.g., a web browser) and the server. Response headers, sent from the server back to the client, provide details about the response itself, such as the content type, content length, server software, caching policies, cookies, security directives (like Content Security Policy or HSTS), and redirection status.

Why Use Our Free HTTP Headers Checker?

• Debug Website Issues: Analyze headers to troubleshoot problems related to caching, redirects, content types, or server configurations.
• SEO Audits: Check for important SEO-related headers like `X-Robots-Tag`, `Link` (for rel=canonical, hreflang), `Vary`, and caching headers.
• Security Analysis: Inspect security headers such as `Content-Security-Policy`, `Strict-Transport-Security`, `X-Content-Type-Options`, `X-Frame-Options`, and `X-XSS-Protection`.
• Understand Caching Behavior: View `Cache-Control`, `Expires`, `ETag`, and `Last-Modified` headers to see how browsers and proxies are instructed to cache content.
• Check Redirect Chains: See the `Location` header for 301/302 redirects. (Note: This tool fetches the final destination's headers after following redirects via the proxy).
• Developer Tool: A quick way for web developers to inspect the headers of any live URL. This website header viewer is invaluable.

How to Use the HTTP Header Viewer

• Enter URL: Type or paste the full URL (including `http://` or `https://`) of the webpage whose HTTP response headers you want to check.
• Fetch Headers: Click the "Fetch Headers" button.
• View Headers: The tool will attempt to fetch the headers for the given URL (using a CORS proxy) and display them in a formatted list. This includes the HTTP status code and all response headers.
• Analyze: Review the headers for the information you need (e.g., caching directives, server type, content encoding).
• Download (Optional): Click "Download Headers" to save the retrieved headers as a text file.

Note on CORS Proxy: Browsers restrict direct cross-origin requests for security. This tool uses a public CORS proxy to fetch headers from external domains. The proxy makes the request on its server and returns the response (including headers) to our tool. This means the headers you see are what the proxy received. While generally accurate, there might be slight differences or added headers from the proxy itself compared to a direct connection.