UUID Generator
Version 4 UUIDs in the standard 8-4-4-4-12 form, ready to paste.
Results
What this tool does
A UUID is an identifier you can invent without asking anyone whether it is taken. Version 4 fills it with random bits apart from two fixed markers — the version digit and the variant — and relies on the sheer size of the space to make a repeat effectively impossible. That property is what lets two systems that have never met generate keys for the same database and never collide.
Formula
UUID version 4: 122 random bits, with the version and variant fixed
Variables
| Symbol | Meaning | Unit |
|---|---|---|
count | How many | — |
seed | Seed | — |
OUT | UUIDs | — |
F1 | First UUID | — |
Worked example
- How many5
- Seed2026
- UUIDs74a923ac-4019-4125-9e90-34cffc4464ad e105cb6f-aa50-42fd-872f-9dc978cc9af5 21fe2279-4fe0-49e3-a80e-dfc0fe7703de 317fd35b-d39e-482a-9335-2e5065edab53 301f2df1-225e-4409-8f58-9ae86ab25661
- First UUID74a923ac-4019-4125-9e90-34cffc4464ad
Limitations
- The calculation runs entirely in your browser. The values you type are never sent to a server.
Frequently asked questions
Can two UUIDs ever collide?
In principle yes, in practice the numbers make it a non-question. A version 4 UUID has 122 random bits, which is about 5.3 undecillion possibilities; you would need to generate roughly a billion a second for eighty-odd years before the chance of a single collision reached even one in a billion. That is why they can be created independently, on separate machines, with no central register.