Developer-focused tools for headers, DNS, IPs, ports, and more. No login, no tracking, no fluff.
Reach hosts, calculate subnets, geo-locate IPs, and inspect domain ownership.
TCP port reachability checker with multi-port support.
CIDR, subnet, supernet, and wildcard mask calculator.
GeoIP with lat/long, ISP, AS, and 'check my IP' button.
RDAP-first domain lookup with registrar, age, and expiry.
Passive subdomain map via Certificate Transparency + DNS. No packets touch the target.
Grade headers, decode CSP policies, and fingerprint the stack.
Grade any site's security headers from A+ to F.
Visualize Content-Security-Policy directives and get a grade.
Fingerprint the CMS, framework, and 100+ technologies.
Audit email authentication and DNS configuration.
Cross-check IPs against threat feeds and detect anonymizers.
Handy developer utilities with no server-side data storage.
Try a shorter keyword like dns or port.
Metric Tower's dashboard lets you schedule, alert, and track changes for all of these tools and more, continuously, across your whole attack surface.
No credit card required.