UUID Generator
Generate random UUID v4 identifiers instantly. Bulk generate up to 100 UUIDs with one click. Free online UUID generator.
How to Generate UUIDs
Click Generate to create one or more UUID v4 identifiers. Set the count (1-100) for bulk generation. All UUIDs are generated client-side using cryptographically secure randomness.
What is a UUID?
- UUID v4 — A 128-bit identifier generated from random numbers. Format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx.
- Uniqueness — The probability of generating a duplicate UUID v4 is astronomically low (1 in 2^122).
- Common uses — Database primary keys, session IDs, distributed system identifiers, API request tracking.
Frequently Asked Questions
What is UUID v4?
UUID v4 (Universally Unique Identifier version 4) is a 128-bit identifier generated using random or pseudo-random numbers. The "4" in position 13 of the UUID indicates the version, and it follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx.
Can two UUIDs ever be the same?
Theoretically yes, but practically no. With 122 random bits, you would need to generate about 2.71 quintillion UUIDs to have a 50% chance of a single collision. For all practical purposes, UUID v4 values are unique.
Should I use UUIDs as database primary keys?
UUIDs work well as primary keys in distributed systems where sequential IDs are impractical. The trade-off is larger storage (16 bytes vs 4-8 bytes for integers) and slightly slower indexing. For single-database apps, auto-increment integers are often simpler.