Enter an IPv4 network, then click a tile to split it into two halves — click again to merge it back. Build a full subnet tree, expand and collapse as you go.

Try: 10.0.0.0/8 192.168.1.0/24 172.16.0.0/16 203.0.113.0/27
💡 Click a subnet to split (▶) or merge (▼). Use the copy buttons or just select any text in a tile to copy it.