IPv4 & IPv6 subnet calculator, DNS lookup, ping, traceroute, VLSM designer, and email authentication checks — all in one fast, native app. Live results as you type, synced across your devices.
Free · Right in your browser
IPv4 & IPv6 subnetting, VLSM planning, and mask conversion — instant results, no download or signup required.
Features
Network and broadcast addresses, usable host ranges, masks, wildcard, and host counts — calculated live as you type any CIDR.
Check any domain's SPF, DKIM, and DMARC records at a glance — diagnose deliverability and catch misconfigurations in seconds.
Resolve A, AAAA, MX, TXT, and more records for any hostname with one tap. Large DNSSEC and long TXT responses now load in full — no truncation.
Measure ICMP round-trip time and packet loss, and trace the full network path hop-by-hop to any host.
Carve a network into right-sized subnets with variable-length masks — plan addressing without spreadsheets.
Convert CIDR ↔ mask ↔ wildcard, summarize many networks into one, turn IP ranges into minimal CIDR blocks, and check subnet membership.
Build a library of your most-used subnets, plans, and lookups, with full history — synced privately across all your devices.
A closer look
One download, every Apple platform. Subnet Plus is optimized for each screen size — including a multi-column layout on iPad — and your saved work follows you everywhere via iCloud.
Localization
Free to download — the network toolkit engineers have trusted since 2013.
