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/web-analyzerOpen →
Web Analyzer
Every check for one domain on a single page: server, network, DNS, whois, SSL, and blacklists./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/ssl-checkOpen →
SSL Certificate Checker
Certificate expiry, domain name match, intermediate chain, and TLS versions./en/tools/reverse-dns-lookupOpen →
Reverse DNS (PTR) Lookup
PTR records of an IP or a whole /24, with forward-confirmed and generic-name checks for mail servers./en/tools/dns-leak-testOpen →
DNS Leak Test
Which DNS resolvers your browser uses, and whether DNS queries leak outside your VPN./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 →
Web analyzer
Location, ISP, and network details for any IP or domain./en/whoisOpen →
IP lookup
Registrar, dates, expiry, and nameservers for a domain./en/asOpen →