Prefixloom: Subnet Planner

About 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
- 110 original offline technical plates
- 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.