Network tools

    Subnetting, address maths and MAC utilities.

    IPv4 subnet calculator

    Work out network address, broadcast, mask, host range and size from CIDR.

    IPv4 address converter

    Convert an IPv4 address to decimal, hex, binary and IPv6 forms.

    IPv4 range expander

    Turn a start and end IP into the smallest CIDR block that contains them.

    IP in range checker

    Check whether an IPv4 address falls inside one or more CIDR ranges.

    MAC address lookup

    Find the vendor that owns a MAC address OUI prefix.

    MAC address generator

    Generate random MAC addresses in the separator format you need.

    IPv6 ULA generator

    Generate a RFC 4193 unique local IPv6 address prefix.

    Everything here runs on your machine

    These 7 network tools are plain client-side JavaScript served as static files. There is no backend to receive what you paste, no account to create and no usage limit. Open your browser's network panel while you work and you will see the page load, then nothing else.