HTTP Header Checker
Inspect response headers for a URL.
The HTTP Header Checker on Tool World provides a powerful yet simple way to peer behind the curtain of any web request. Ever wondered how a website tells your browser to cache content, or how it enforces security policies like HSTS? This online utility fetches a specified URL and then meticulously displays all the HTTP response headers returned by the server.
Developers frequently use this tool to debug complex issues, such as verifying Cross-Origin Resource Sharing (CORS) configurations, ensuring proper redirects are in place, or confirming content types. SEO professionals can quickly check Location headers for redirect chains or identify Link: <...>; rel="canonical" to understand how search engines interpret pages. Security experts can validate the presence and correctness of headers like Content-Security-Policy, X-Frame-Options, or Strict-Transport-Security, crucial for protecting users. Webmasters can ensure their caching headers, such as Cache-Control and Expires, are optimally configured for faster page loads.
To use it, simply enter the target URL into the input field. The output will be a clear, organized list of all response headers, each with its key and corresponding value. For instance, you might see Content-Type: text/html; charset=utf-8 or Set-Cookie: PHPSESSID=.... A key tip for using the HTTP Header Checker is to remember it focuses solely on the initial response headers from the primary document request. It won't display client-side request headers, nor will it follow or show headers for all linked resources like images, scripts, or stylesheets embedded within the page. This makes it ideal for diagnosing server-level responses to a direct URL request.
How to use HTTP Header Checker
Access the Tool
Navigate to the HTTP Header Checker tool page on Tool World to begin inspecting website headers.
Enter URL
Type or paste the full URL of the website or specific resource you wish to inspect into the designated input box. Ensure the URL starts with http:// or https://.
Initiate Check
Click the "Check Headers" button to send the request to the server. The tool will then fetch the specified URL.
Review Results
Examine the displayed list of HTTP response headers. Each header name and its corresponding value will be presented clearly for your analysis.
Analyze Specifics
Look for headers relevant to your purpose, such as Cache-Control for caching directives, Content-Security-Policy for security configurations, or Location for redirect paths.
Frequently Asked Questions
What is an HTTP header?
HTTP headers are name-value pairs exchanged between a web client (like a browser) and a server with every HTTP request or response. They carry essential metadata about the request or response, such as content type, caching instructions, server information, and security policies.
Can the HTTP Header Checker see request headers sent by my browser?
No, this tool specifically shows the response headers sent back by the web server after it processes a request for the URL you provide. It does not display the request headers that your browser might send, nor does it mimic all the request headers a specific browser might use.
How can I check headers for resources like images or CSS files?
To check headers for specific embedded resources, you must enter the direct URL of that image, stylesheet, or script into the HTTP Header Checker. The tool processes only the exact URL provided, not linked elements within a page.
What common HTTP response headers should I look for?
Important headers include Content-Type (media type), Cache-Control (caching directives), Set-Cookie (session management), Location (redirects), Server (server software), X-Frame-Options or Content-Security-Policy (security), and Strict-Transport-Security (HSTS).
Is there a limit to how many headers the tool can display?
Generally, no specific limit exists on the number of headers displayed by the HTTP Header Checker. It will attempt to show all valid response headers sent by the server for the provided URL. However, extremely large or malformed header sets might be truncated or cause errors.
Does this tool follow redirects?
Yes, the HTTP Header Checker typically follows HTTP redirects (3xx status codes) and displays the headers of the final destination URL. It will also often indicate if a redirect occurred, sometimes showing an intermediate Location header before displaying the final response.