Registration data over RDAP — the modern replacement for WHOIS — alongside live DNS records. Also works for IP addresses and AS numbers.
Lookups run from your browser straight to IANA, the authoritative registry, and Cloudflare's DNS resolver. Nothing passes through this site's servers.
Browser Info
See everything your browser reveals — user agent, screen, GPU, network, and more.
CIDR / Subnet Calculator
Enter CIDR notation to see the network details, host range, and subnet mask.
WCAG Contrast Checker
Check text and background contrast ratio against WCAG 2.1 AA and AAA thresholds.
HTTP Status Code Reference
A searchable reference of all HTTP status codes with descriptions and use cases.