Network & IP Tools

Check your connection and work out network numbers without installing anything. The subnet tools calculate IP subnets, convert CIDR notation to an IP range and back, handle IPv6 subnets, expand and compress IPv6 addresses, and convert an IP address between decimal, binary and hex. A subnet mask cheat sheet, a MAC address formatter and a port number reference keep the details you keep forgetting within reach. The bandwidth calculator and data transfer time calculator answer practical questions — how long a download or an upload will actually take at a given speed. A latency tester measures your connection to the Cloudflare edge, and status checks report whether you are online, what kind of connection you are on, and your screen resolution and browser details. DNS tools explain DNS records in plain language and generate SPF and DMARC records for setting up email authentication on a domain. Network engineers use these to plan subnets and verify settings, and website owners use them to check a connection or prepare a domain's records. Most tools run entirely in your browser; the latency test necessarily talks to a network edge to measure the round trip, and it says so on the page. Free, with no account.