Free HTTP headers checker tool to view response headers for any URL. Check security headers, content type, caching, server info, and status codes.
HTTP headers are the behind-the-scenes data that a web server sends with every page load. They control everything from caching and content type to security policies and redirects. If you're debugging a website issue or auditing security, headers are where you start.
Our free HTTP Headers Lookup tool fetches and displays all response headers for any URL.
What You Can Learn
- Server — What web server software is running (Apache, Nginx, etc.)
- Content-Type — How the server is delivering content
- Cache-Control — How browsers and CDNs should cache the page
- Security headers — CSP, HSTS, X-Frame-Options, and more
- Status code — 200 (OK), 301 (redirect), 404 (not found), 500 (error)
- CORS headers — Cross-origin resource sharing settings
Why It Matters
Missing security headers are a common finding in website security audits. For example, if Strict-Transport-Security is missing, your site could be vulnerable to downgrade attacks. If X-Content-Type-Options: nosniff is absent, browsers might interpret files differently than intended.
Whether you're a developer debugging a caching issue or a security-conscious site owner, the HTTP headers checker gives you the raw data servers reveal about themselves.