UUID / GUID Generator
Generate Version 4 UUIDs (random) or Version 7 (timestamp-prefixed, sortable). Each is 128 bits of randomness — collision-free for practical purposes.
Inputs
About UUID / GUID Generator
v4 vs v7
v4 is fully random — great when you want zero correlation between IDs. v7 prefixes 48 bits of timestamp, making IDs sortable by creation time — great for database primary keys where insertion order matters.
Collision risk
v4: 122 bits of randomness means you’d need to generate billions per second for centuries before a collision becomes likely. v7: 74 random bits per millisecond — still astronomically safe for most applications.
When to use
v4: API keys, session tokens, random correlation IDs. v7: database primary keys, log identifiers, anywhere creation-order matters. Always preserve the original format when storing or comparing.