HTTP Headers Checker
Enter a URL to inspect all HTTP response headers returned by the server.
Server processing — your query is handled securely on our servers.
How to use HTTP Headers Checker
The HTTP Headers tool fetches any URL and shows the full set of response headers the server returns, including status code, content type, caching directives, security headers and redirects. Headers control how browsers cache, secure and render a page, so inspecting them is essential when debugging why a resource is not being cached, why a security policy is not applying, or whether a redirect chain is configured correctly. The tool follows redirects and reports each hop so you can see the complete journey from the requested URL to the final response.
- Enter the full URL you want to inspect, including https://.
- Click Fetch to request the URL and capture its response headers.
- Review the status code and each header returned by the server.
- Follow any redirect chain shown to confirm the final destination.
- Check security and caching headers against your expectations.
Key security headers to look for
Modern sites rely on a handful of response headers to harden the browser against common attacks. Strict-Transport-Security forces HTTPS, Content-Security-Policy restricts which scripts and resources may load, X-Content-Type-Options stops MIME sniffing, and X-Frame-Options or a frame-ancestors policy prevents clickjacking. If these headers are missing or misconfigured, a security scanner will flag the site, so verifying them here is a quick way to confirm your hardening is actually being sent to clients.
| Header | Protects against |
|---|---|
| Strict-Transport-Security | Protocol downgrade / SSL stripping |
| Content-Security-Policy | Cross-site scripting (XSS) |
| X-Content-Type-Options | MIME-type sniffing |
| X-Frame-Options | Clickjacking |
Caching and content headers
Cache-Control, ETag and Expires headers tell browsers and CDNs how long they may reuse a response, which directly affects page speed and server load. Content-Type declares the media type and character set so the browser renders the body correctly. If a page seems to ignore your updates, an aggressive Cache-Control max-age is often the cause; if text appears garbled, a missing or wrong charset in Content-Type is the usual culprit. Reading these headers turns guesswork into a definitive diagnosis.
Glossary
- Status code
- A three-digit number such as 200, 301 or 404 that summarises the result of an HTTP request.
- Cache-Control
- A header that dictates how and for how long a response may be cached.
- ETag
- A validator token that lets a client revalidate a cached resource without re-downloading it.
- CSP
- Content-Security-Policy — a header restricting which resources a page may load to mitigate XSS.
- Redirect
- A 3xx response that points the client to a different URL to continue the request.
Related reading
Frequently Asked Questions
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Why use HTTP Headers Checker?
- Real-time DNS lookups using live resolver queries
- Supports IPv4 and IPv6 addresses
- No software to install — runs entirely in the browser
- Results include TTL values and record priority
Common use cases
- Verify DNS propagation after updating nameservers
- Check MX records when troubleshooting email delivery
- Look up SPF/DKIM/DMARC records for email security audits
- Test whether a SSL certificate is valid and up to date
- Find the IP address behind a domain name
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