Network
Subnetting, DNS, IP conversion and the everyday lookups network engineers do dozens of times a day. Built by someone who actually plans address space — the subnet calculator does VLSM and shows the mask boundary bit by bit.
Subnet CalculatorCalculate IPv4 subnets, masks and host ranges, split blocks (VLSM), and see the network at the bit level.DNS LookupLook up DNS records (A, AAAA, CNAME, MX, TXT, NS, CAA) for any domain, or resolve a dynamic-DNS hostname to its current IP.What Is My IPSee your public IP plus country, city, ASN and network — read at the edge, never stored.IP Address ConverterConvert an IPv4 address to its decimal, binary and hexadecimal forms and back, in your browser.IPv6 Expand / CompressExpand an IPv6 address to its full form or compress it with :: notation, both ways in your browser.URL ParserParse any URL into protocol, host, port, path, query parameters and hash, instantly in your browser.User-Agent ParserSee your own user-agent and parse any UA string into OS, browser, engine and device type.chmod CalculatorConvert Unix file permissions between checkboxes, octal (755) and symbolic (rwxr-xr-x) — kept in sync.MAC Address FormatterReformat a MAC address into colon, hyphen, Cisco dot and bare forms in upper or lower case.