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UUID Variants Generator
Generate nil, v1, v4, and v5 UUIDs at once
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About this tool
Generate a full set of UUID variants in one click — nil UUID, time-based v1, random v4, and name-based v5 — for comparing or testing against different UUID formats.
Frequently asked questions
What's the difference between UUID v1, v4, and v5?
v1 is time-based (derived from a timestamp and network identifier — technically traceable to when/where it was generated). v4 is fully random, the most common choice for general-purpose unique IDs. v5 is name-based, deterministically generated from a namespace and name (the same input always produces the same UUID) — useful when you need a repeatable, unique identifier for a given value.
What is the nil UUID?
A UUID that's all zeros (00000000-0000-0000-0000-000000000000) — used as a well-known placeholder or sentinel value meaning "no UUID"/"unset".
Need just a single random UUID?
Use our plain UUID Generator instead — it returns one v4 UUID per click without the other variants.