HTTP Header Checker
Inspect the hidden response metadata sent back by web servers.
💡 In Plain English: What is an HTTP Header?
When your web browser visits a site, the server attaches an invisible "shipping label" (header) to the page. This label tells your browser how long to save the page (Cache-Control), what security rules to follow (HSTS, CSP), and what server technology is running behind the scenes.
What are security headers?
Learn how HSTS, CSP, and X-Frame-Options protect websites in our guide.