Prefixloom: Subnet Planner

Prefixloom is a focused local subnet planning desk for network engineers, homelab operators, consultants, students, and small teams still coordinating addresses in spreadsheets. Compare assigned and reserved addresses with projected growth before a block becomes an operational constraint. KEY FEATURES - CIDR capacity and utilization model - Projected-growth multiplier - Reserved-address accounting - Address pressure visualization - VLAN and owner records - Editable current and proposed intent - CSV inventory import - Offline planning packet - Local PDF and JSON export - No account, ads, analytics, tracking, IAP, or subscription Prefixloom performs deterministic IPv4 capacity planning from recorded inputs; it does not discover live devices, reserve addresses, configure routers, or replace authoritative IPAM. Verify overlap, routing, DHCP, VRFs, security zones, cloud reservations, and current assignments before deployment.