UUID Generator
Create version 4 (random) UUIDs for database keys, cache keys, testing or any unique identifier. Generate a single value or a batch, and copy them all at once.
What this means
A UUID is a 128-bit identifier formatted as 32 hex digits with four hyphens. Version 4 uses random bytes, making collisions astronomically unlikely.
How we calculate it
Formula
16 random bytes with version (4) and variant bits set, formatted 8-4-4-4-12.Worked example
Create a batch of 5 UUIDs for seeded data.
- 1Set count to 5.
- 2Generate — each UUID is unique.
- 3Copy the batch into your code.
Important assumptions
- UUIDs are random, not sequential or derived from timestamps.
Frequently asked questions
What is a UUID v4?
A random 128-bit identifier with the version digit set to 4, per RFC 4122. It is used wherever a globally unique key is needed.
Are UUIDs always unique?
The random space is so large that the chance of two colliding is negligible — around one in 3.4 × 10^38.
Guide
Password Generator Guide: Length, Entropy and Security
The strongest passwords are long and random. Here is why length matters more than complexity.
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