Network Tools
Free tools for looking up and calculating IP addresses. All of them work in the browser, and some from a terminal with curl too.
01 / tools
Pick a tool.
/en/tools/dns-lookupOpen →
DNS Lookup
A, MX, NS, TXT and more, plus SPF, DMARC, DKIM, and DNSSEC checks./en/tools/dns-propagationOpen →
DNS Propagation Checker
Whether a record change shows up at 18 public resolvers, compared with the domain's nameserver./en/tools/blacklist-checkOpen →
IP & Domain Blacklist Check
Whether your IP or mail server is on Spamhaus, Barracuda, SpamCop, and other email blacklists./en/tools/ipv4-subnet-calculatorOpen →
IPv4 Subnet Calculator
Network, broadcast, host range, subnet mask, and subnet splits from a CIDR prefix./en/tools/ipv6-subnet-calculatorOpen →
IPv6 Subnet Calculator
Network prefix, address range, /64 count, full notation, and prefix splits./enOpen →
IP lookup
Location, ISP, and network details for any IP or domain./en/whoisOpen →
Whois lookup
Registrar, dates, expiry, and nameservers for a domain./en/asOpen →