Networking tools.
Clear answers.
Find your address, understand a network, or check a service. Focused tools with clear results and a practical next step.
9 tools, ready when you are
Public IP checker
See the IPv4 or IPv6 address visible to this server, with automatic provider and approximate location details.
Instant resultOpen tool → ReachabilityOpen port checker
Test whether selected TCP ports on your public IP accept an inbound connection from our server.
Permission requiredOpen tool → AddressingIPv4 subnet calculator
Calculate the network address, subnet mask, broadcast address, host range, wildcard mask, and address count.
Runs in your browserOpen tool → Address analysisIPv4 & IPv6 analyzer
Validate an address, expand IPv6 notation, and identify private, public, shared, and reserved ranges.
Runs in your browserOpen tool → IPv6 addressingIPv6 subnet calculator
Find exact prefix boundaries, address counts, and child subnet counts. Split delegated prefixes without generating huge lists.
Runs in your browserOpen tool → Address planningIP range to CIDR converter
Cover an inclusive IPv4 range with the smallest exact set of CIDR blocks, without adding unwanted addresses.
Runs in your browserOpen tool → IPv4 & IPv6CIDR membership checker
Check one address against a list of CIDR networks and inspect normalized boundaries, matches, and family differences.
Runs in your browserOpen tool → Transfer planningFile transfer time calculator
Estimate uploads and downloads with explicit decimal or binary file units, rate units, and effective-rate assumptions.
Runs in your browserOpen tool → Command line / APIPublic IP API for curl
Get your address as plain text or JSON from this domain. Add provider and approximate location details when you need them.
No API keyRead documentation →A result is only useful in context.
These tools observe one part of a connection. Pair the output with the correct next step.
That is normal on a dynamic ISP connection. Recheck after reconnecting your modem or VPN.
Check the service, host firewall, router forwarding, carrier-grade NAT, and whether your ISP filters it.
Start with the CIDR prefix. It determines which bits identify the network and which identify a host.