The toolbox
Practical tools.
Small utilities for networking and connected technology. Everything here runs locally in your browser.
IPv4 · Networking
Subnet calculator
Calculate network and broadcast addresses, subnet masks, host ranges and address capacity from CIDR notation.
Open calculator →Wi-Fi · QR code
Wi-Fi QR generator
Create and download a QR code that connects phones and tablets to your wireless network. Your details stay on your device.
Create a QR code →VLSM · Network design
VLAN & subnet planner
Allocate right-sized, non-overlapping IPv4 subnets from a parent network and export the finished VLAN plan.
Plan a network →DNS · Zone records
DNS record builder
Build and validate common DNS records with readable explanations and copy-ready zone-file output.
Build DNS records →MAC · Vendor lookup
MAC address lookup
Identify the registered hardware vendor for a MAC address or OUI using the MACVendors database.
Look up a vendor →DNS · Troubleshooting
DNS lookup
Query public DNS records through Cloudflare’s 1.1.1.1 resolver with TTL, DNSSEC and dig-style response details.
Run a DNS query →