Generate Unique Local Addresses for private IPv6 networks — random 40-bit global IDs in fc00::/7 space, no coordination needed.
Content reviewed October 2026 · About Toolzum
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Unique Local Address — private IPv6 space (fc00::/7) for internal networks, like 192.168.x.x for IPv4.
Link-local (fe80::/10) works on one link only; ULAs route across your whole organization.
40 random bits — generated once per site, practically guaranteed unique without coordination.
8 random bytes from getRandomValues: group 1 is forced to fd, every byte is hexed with 2-digit padding, joined and regrouped into 4-hex-letter blocks, shortened once via (:0)+: to ::, plus a Subnet row of fdXX:XXXX:XXXX::/48.
No — generation runs locally in your browser, free with no signup.
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