How to use the UUID / GUID Generator
- Pick v4 or v7 and a quantity.
- Toggle uppercase or no-hyphen formatting.
- Click Generate, then copy or download.
About this tool
A UUID (Universally Unique Identifier, also called a GUID) is a 128-bit value written as 32 hex digits in five groups, e.g. 3f2b8c1e-7a4d-4e9b-9c2a-1d5e6f7a8b9c. Systems use them as database keys and request IDs because they can be generated anywhere without coordination and practically never collide.
v4 or v7?
Version 4 is 122 bits of randomness — the classic choice. Version 7 (RFC 9562, 2024) puts a millisecond Unix timestamp in the first 48 bits, so IDs sort by creation time. That keeps B-tree database indexes compact and inserts fast, which is why many teams now default to v7 for primary keys.
All values here come from crypto.getRandomValues, the browser's cryptographically secure generator — not Math.random.
Frequently asked questions
Can two UUIDs collide?
For v4 you'd need to generate about 2.7 quintillion to have a 50% chance of one duplicate.
Is GUID the same as UUID?
Yes — GUID is Microsoft's name for the same standard.
Which version for database keys?
v7, if your stack supports it, because it is time-sortable.