About this tool
Generate one or many version 4 UUIDs — the random variant — using the browser's built-in crypto.randomUUID, which is RFC 4122 compliant and cryptographically random. Bulk generation up to 100 at a time with a single copy action.
A v4 UUID carries 122 random bits, making collisions so improbable they are ignored in practice: you could generate a billion UUIDs per second for decades before a duplicate became likely. That is why UUIDs are the default for database keys, request IDs and distributed systems where coordination-free uniqueness matters.
How to use it
- Set how many UUIDs you need.
- Click Generate.
- Copy one or the whole batch.
Frequently asked questions
What do the UUID versions mean?
v1 embeds a timestamp and MAC address, v4 is fully random, v5 is name-based hashing, and the newer v7 combines a timestamp with randomness for sortable IDs. v4 is the common general-purpose choice.
Can two v4 UUIDs collide?
Theoretically yes, practically no — with 122 random bits, the probability is negligible at any realistic scale.
Why does the third group always start with 4?
That digit encodes the UUID version. The first character of the fourth group encodes the variant (8, 9, a or b).