Enter any URL to inspect HTTP response headers, security settings, and caching policies.
Frequently Asked Questions
What are HTTP response headers?
HTTP response headers are key-value pairs sent by a web server along with the requested content. They provide metadata about the response such as content type, caching policies, security settings, and server information.
Why should I check HTTP headers?
Checking HTTP headers helps you verify security configurations (CORS, CSP, HSTS), caching policies, server software, and content encoding. It's essential for debugging web issues and auditing site security.
What are security headers?
Security headers include Strict-Transport-Security (HSTS), Content-Security-Policy (CSP), X-Content-Type-Options, X-Frame-Options, and X-XSS-Protection. They instruct browsers to enforce security protections.
How do I check headers for a website?
Enter the full URL (including https://) in the input field above and click Analyze. The tool fetches the page and displays all response headers in a formatted table.
What does Cache-Control do?
Cache-Control tells browsers and CDNs how long to cache a resource. Values like max-age=3600 mean cache for 1 hour. no-store means never cache. Proper caching improves load times.
What is Content-Security-Policy (CSP)?
CSP is a security header that prevents cross-site scripting (XSS) attacks by specifying which sources of content the browser is allowed to load, such as scripts, styles, and images.
What is CORS?
Cross-Origin Resource Sharing (CORS) is controlled by the Access-Control-Allow-Origin header. It determines whether a web page from one domain can request resources from another domain.
Is this tool free to use?
Yes, this HTTP header checker is completely free with no signup required. It runs entirely in your browser and uses a CORS proxy to fetch headers from any URL.