HTTP Headers Lookup
About HTTP Headers Lookup
Inspect HTTP response headers for any URL. View server type, caching directives, content-type, security headers (HSTS, CSP, X-Frame-Options), compression settings, and more. Useful for debugging web applications, checking CDN configuration, verifying security headers, and diagnosing 301/302 redirect chains.
More Checker tools
DNS Lookup
Free online DNS lookup tool. Query DNS records for any domain including A, AAAA, MX, TXT, CNAME, NS, SOA, and PTR records. Instantly check where a domain points, find mail server records, verify TXT records for SPF, DKIM, and DMARC, and diagnose DNS propagation issues. No installation required — works directly in your browser.
IP Lookup
Look up detailed information about any IP address. Find the hostname, ISP, organization, country, and region associated with an IPv4 or IPv6 address. Useful for network diagnostics, identifying the origin of traffic, investigating suspicious connections, and verifying server configurations. Free, instant, and requires no sign-up.
Reverse IP Lookup
Perform a reverse IP lookup to find the hostname and domains associated with an IP address. Enter any IPv4 or IPv6 address to resolve its PTR record and discover what servers or websites are hosted on that IP. Useful for network auditing, cybersecurity investigations, and verifying server identity.
SSL Lookup
Check SSL/TLS certificate details for any domain. View the certificate issuer, subject, validity dates, and days remaining before expiration. Quickly verify whether a site's HTTPS certificate is valid, identify certificate authority (CA), and monitor certificate expiry to prevent downtime. Supports custom ports.