Network Tools

Private browser-based network tools for IPv4 subnets, common TCP/UDP ports, and HTTP URL analysis. No network requests.

3 tools

Network Tools answers three lookup-style questions about addresses and connections without touching a network. The IP Subnet Calculator expands a CIDR block or an address-and-mask into its network, broadcast, host range and counts. The Port Number Lookup searches a curated table of common TCP and UDP ports by number, service or protocol. The URL Parser & Analyzer breaks a link into its scheme, host, port, path, query and fragment and flags things like embedded credentials or Punycode. None of them contacts a host, so every result describes structure or reference data, never live reachability.

Which tool should I use?

Use the IP Subnet Calculator when you have a CIDR block or an address plus a subnet mask and need the network, broadcast, usable-host range or address count; /31 and /32 are handled without the usual two-address deduction.
Use the Port Number Lookup to recall what a port is conventionally for, or which port a service usually uses — it is a reference, not a scanner, and the table is deliberately short.
Use the URL Parser & Analyzer to inspect a suspicious or complex link's parts before doing anything with it; it never opens the link and cannot judge whether the destination is safe.

Limitations and things to know

IPv4 only — there is no IPv6 subnetting, and the subnet mask must be contiguous.
"Private" means the RFC 1918 ranges only (10/8, 172.16/12, 192.168/16); loopback, link-local and carrier-grade NAT addresses are all reported as public.
The port table is a short curated selection cross-checked against IANA, not the full registry; a real service may use a different port.
The URL analyzer accepts http and https only, up to 4,096 characters, and rejects control characters; it describes the URL's structure and cannot establish safety, ownership, reputation or whether the address resolves.