Network & Web
IP, DNS and subnet utilities for network debugging. Tools that must call an external service say so clearly on the page.
- DNS Lookup Query A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records for any domain through Cloudflare's DNS-over-HTTPS resolver, with TTLs shown and copyable results.
- Subnet Calculator Calculate network address, broadcast, usable host range, netmask and wildcard for any IPv4 or IPv6 CIDR block — entirely in your browser, RFC 3021 aware.
- What Is My IP Address Shows the public IPv4 and IPv6 addresses your connection presents to websites, checked via Cloudflare with an ipify fallback, with one-click copy buttons.
Debugging a connectivity or DNS problem usually starts with one of three questions. To learn the public address the internet sees you from — both IPv4 and IPv6, plus the rough geolocation and ISP that resolve from it — open What Is My IP Address?. To find out what a domain's records actually say — its A and AAAA addresses, MX mail routing, TXT verification strings, NS delegation — the DNS Lookup queries them for you. Both of those necessarily reach an external resolver to get their answer, and each page says so plainly at the top; unlike the rest of the site, they cannot run purely offline.
The Subnet Calculator, by contrast, is pure arithmetic that stays in your browser: give it a CIDR block like 10.0.0.0/24 and it returns the network and broadcast addresses, the usable host range and how many addresses the mask covers — handy when you are carving up a VPC or sizing a DHCP pool.
What your address gives away is a common worry, and a widely oversold one. The guide to what your IP reveals covers what geolocation genuinely resolves to — a city and an ISP, not your front door — who along the path sees the address, and what a VPN actually moves versus what it leaves exposed.