HTTP Header Inspector

Parse raw HTTP headers, check security score, build custom headers, and browse the reference.

Last reviewed: April 2026
Reviewed by , software engineer · last updated April 2026

New to this tool? Click here for instructions

Raw Headers
Parsed Headers
Paste headers on the left to inspect them.
Paste raw HTTP headers to parse and inspect them.

How to use HTTP Header Inspector

To use the HTTP Header Inspector, follow these steps:

1. Paste the raw HTTP headers you want to inspect into the provided text area.

2. Click the 'Parse' button to analyze the headers.

3. The tool will display the parsed headers, including explanations and security scores.

4. You can also build custom headers by entering the desired values and clicking 'Build'.

5. The reference section provides detailed explanations of all common HTTP headers.

When to use HTTP Header Inspector

Use the HTTP Header Inspector when you need to:

1. Debug web applications by inspecting the headers being sent and received.

2. Optimize web performance by caching resources effectively.

3. Secure your website by implementing and verifying security headers.

4. Build custom headers for API requests or responses.

5. Ensure compliance with web standards and security best practices.

How it works

The HTTP Header Inspector works by:

1. Accepting raw HTTP headers as input.

2. Parsing the headers to extract key-value pairs.

3. Providing explanations for each header, including its purpose and potential security implications.

4. Offering a security score based on the presence and configuration of recommended headers.

5. Allowing users to build custom headers by entering the desired values.

Tips, Edge Cases, and Limitations

Tips:

1. Always verify the security scores and explanations provided by the tool.

2. Use the reference section to learn more about each header and its best practices.

3. Be aware that the tool is 100% client-side and does not send any data to a server.

Edge Cases:

1. The tool may not recognize or explain custom headers that are not widely used.

2. The security score is based on a set of recommended headers and may not cover all potential security risks.

Limitations:

1. The tool does not perform any actions on your server or network.

2. It does not provide real-time monitoring or alerts for security issues.

3. The tool is limited to client-side operations and does not interact with external services.

Frequently Asked Questions

The Content-Security-Policy (CSP) header helps prevent cross-site scripting (XSS) attacks by defining which resources the browser may load.
HSTS (HTTP Strict Transport Security) forces HTTPS connections for a specified duration, enhancing security by preventing man-in-the-middle attacks.
The Cache-Control header controls caching behavior for both browsers and CDNs, helping optimize web performance by reducing the number of requests.
The X-Frame-Options header prevents clickjacking attacks by specifying whether a web page can be displayed in a frame, iframe, or object.
Every website should have the following security headers: Content-Security-Policy, Strict-Transport-Security, X-Frame-Options, and X-Content-Type-Options. Additionally, it's recommended to use Referrer-Policy and Access-Control-Allow-Origin (CORS) headers as needed.