HTTP Headers Checker

What is HTTP Headers Checker?

HTTP response headers are metadata sent by a web server with every response. They control caching, security policies, content types, and server identification. The HTTP Headers Checker fetches any URL via Cloudflare's edge and displays all response headers in a structured table, plus a security scorecard for HSTS, CSP, X-Frame-Options, and other critical headers. Misconfigured headers can cause caching bugs, security vulnerabilities, or broken rendering.

Real-world use cases include auditing security headers before launch, debugging cache behavior, verifying CORS and content-type settings, identifying server software, and ensuring HSTS and CSP are correctly configured. Security teams use it for compliance checks; developers use it to troubleshoot caching and CORS issues.

How to Use HTTP Headers Checker

1. Enter a URL (including https://) in the Website URL field.
2. Click Check Headers or press Ctrl+Enter. The tool fetches the page and returns all response headers.
3. View the structured table: each header name and value is listed. The security scorecard shows which key headers are present or missing.
4. Check the stat grid: HTTP status, server, header count, and security grade (A–F).
5. Switch to Raw view for JSON. Open Advanced to toggle security analysis or change request method (GET/HEAD).

Tips & Best Practices

Key headers to look for: Strict-Transport-Security (HSTS), Content-Security-Policy (CSP), X-Content-Type-Options: nosniff, X-Frame-Options. Missing headers may indicate security gaps. Use Ctrl+Shift+C to copy and Esc to clear. For uptime checks, use our Website Status Checker. For redirect chains, use the Redirect Checker.

When to Use This Tool

Use the HTTP Headers Checker when auditing security, debugging caching, or verifying server configuration. Pair it with the Website Status Checker for uptime, or the Redirect Checker to trace redirect chains.

Key Headers to Check

Cache-Control — Controls browser and CDN caching. Look for max-age, no-store, or s-maxage directives. Incorrect caching is one of the most common causes of stale content.

Content-Security-Policy (CSP) — Defines which resources the browser may load. A strong CSP blocks cross-site scripting (XSS) attacks. Missing CSP is a common security gap.

Strict-Transport-Security (HSTS) — Forces HTTPS connections. If missing, users accessing your site via HTTP are vulnerable to downgrade attacks.

X-Frame-Options — Prevents your page from being embedded in an iframe, blocking clickjacking. Should be set to DENY or SAMEORIGIN.