HTTP Header Checker - View & Analyze HTTP Response Headers

🔍 HTTP Header Checker

Check and analyze HTTP response headers from any website. View Cache-Control, Server type, Content-Encoding, and more.

📋 All Response Headers:

Online HTTP Header Checker: Inspect Server Response Headers

Every time you visit a website, your browser and the web server exchange a set of "headers." These headers contain critical information about the connection, the server, and the content being delivered. Our HTTP Header Checker allows you to peek behind the curtain and view these headers for any URL, helping you troubleshoot configuration issues, optimize performance, and improve your site's security.

Why You Need to Check HTTP Headers

Understanding HTTP headers is vital for anyone managing a website or a web application.

Debug Server and Redirection Issues

Are your redirects working correctly? Use this tool to see if your server is returning a 301 Moved Permanently or a 302 Found. You can also identify infinite redirect loops that prevent users from reaching your content.

Optimize for SEO and Performance

Search engine crawlers rely on HTTP headers to understand your site. Checking headers like Cache-Control and Vary ensures your content is cached efficiently, reducing load times. Furthermore, checking for the X-Robots-Tag can help you manage how your pages are indexed.

Key Information You Can Extract

Our tool provides a comprehensive breakdown of the most important headers returned by a web server.

1. HTTP Status Codes

Get the definitive status of your request, such as 200 OK, 404 Not Found, or 503 Service Unavailable. This is the fastest way to verify if a page is live or down.

2. Server Identification

Identify the technology powering the website. The Server header often reveals whether the site is running on Nginx, Apache, LiteSpeed, or behind a CDN like Cloudflare.

3. Caching and Compression

Inspect headers like Content-Encoding: gzip to see if your server is compressing data to save bandwidth. Check Cache-Control and Expires to verify your browser-side caching strategy.

4. Security Configuration

Quickly see if critical security headers are active, such as:

  • Strict-Transport-Security (HSTS)

  • Content-Security-Policy (CSP)

  • X-Frame-Options

How to Use the HTTP Header Checker

  1. Enter the URL: Type or paste the full website address (including http:// or https://) into the input box.

  2. Click Check: Hit the "Check Headers" button to initiate the request.

  3. Analyze Results: Review the neatly organized list of keys and values returned by the server.

  4. Troubleshoot: Use the data to adjust your .htaccess, nginx.conf, or application-level header settings.

Technical Insights: Common HTTP Headers Explained

The Role of the 'Set-Cookie' Header

This header tells the browser to store a cookie. By inspecting this, you can verify if your session cookies are being set with the Secure and HttpOnly flags, which are essential for protecting user data.

Understanding 'Access-Control-Allow-Origin'

Working with APIs? This header is the backbone of CORS (Cross-Origin Resource Sharing). Our tool helps you verify if your server is allowing requests from the correct domains, preventing "CORS policy" errors in the browser console.

Frequently Asked Questions (FAQ)

What is the difference between Request and Response headers?

Request headers are sent by the client (browser) to the server. Response headers—the ones this tool checks—are sent by the server back to the client to provide instructions and information about the data.

Can I check the headers of a mobile-only site?

Yes. This tool acts as a standard client. If the server detects the request and sends a response, the headers will be captured regardless of the intended device.

Is this tool free and private?

Absolutely. You can check as many URLs as you like for free. We do not store the URLs you check or the header data returned, ensuring a private and secure debugging experience.