URL Parser & Analyzer

Calculate IPv4 subnet details locally from either CIDR notation or an address paired with a subnet mask. The calculator validates every octet, prefix length, and contiguous mask before producing a result. It shows the network address, broadcast address, first and last usable hosts, total address count, usable host count, wildcard mask, CIDR prefix, and subnet mask. Point-to-point /31 networks and single-host /32 routes are handled explicitly instead of applying the usual two-address deduction. The private classification refers only to the RFC1918 ranges; other values are described as public or non-private. All arithmetic stays in your browser. The tool does not contact the address, inspect a network, determine ownership, or claim that any host is reachable.

Look up a curated selection of common TCP and UDP port numbers directly in your browser. Search by an exact number, a service name, or a protocol, and optionally narrow the table to TCP or UDP entries. Each result displays the port, protocol, conventional service, a short practical description, and a label distinguishing official or common use from a possible alternate use. Numeric input is checked against the valid range from 0 through 65535, and matching results always use deterministic ordering. The built-in reference is intentionally selective and should not be treated as a complete registry. Actual applications may use different ports. This tool only filters static reference data: it never scans a host, opens a socket, probes a service, or reports whether a port is available.