What is a UUID Generator?
A UUID generator creates Universally Unique Identifiers — 128-bit values used to label records, sessions, or objects without coordination between systems. Each UUID is generated using cryptographically random bits, making the chance of two systems ever producing the same value negligible.
How to Use This UUID Generator
- Set how many UUIDs you need (1 to 100).
- Choose a format — lowercase, UPPERCASE, or no-hyphens.
- Click Generate to produce your UUIDs, one per line.
- Use Copy All to grab the full list.
When Do You Need a UUID Generator?
UUIDs are used as primary keys in databases, unique identifiers for API requests and sessions, file and object names in storage systems, and idempotency keys for payment or webhook processing. Generating them in bulk is useful for seeding test data or pre-allocating identifiers before records are created.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value, usually written as 32 hexadecimal digits in five groups, used to uniquely identify records or objects without needing a central authority to issue them.
UUID v4 vs v1?
UUID v1 is generated from the current timestamp and the device's MAC address, which can leak machine and timing information. UUID v4 is generated entirely from random or pseudo-random bits, making it the preferred choice for most modern applications.
Are UUIDs truly unique?
Not mathematically guaranteed, but collision probability is astronomically low. A UUID v4 has 122 random bits, meaning you'd need to generate billions of UUIDs per second for centuries before a collision became likely.
UUID vs ULID?
ULIDs are similar to UUIDs but are lexicographically sortable because they embed a timestamp prefix, which makes them better suited for database primary keys where insertion order matters. UUIDs are more widely supported and remain the universal default.