UUID / GUID Generator
Generate cryptographically random UUID v4 identifiers, one at a time or in batches of up to 100.
What is a UUID?
A UUID is a 128-bit identifier commonly used for database records, request IDs, distributed systems, test fixtures, and client-generated object IDs. UUID v4 is random, so it does not require a central sequence generator.
Use the single generator for one ID, or batch generate up to 100 UUIDs when creating fixtures, migration scripts, mock API responses, or sample records.
Practical UUID examples
Fixture data: generate a batch of IDs before building sample users, orders, events, or configuration records.
Request tracing: create a correlation ID when testing logs across a frontend, API gateway, and backend service.
Compact output: switch to uppercase or remove hyphens when matching a system that expects a specific UUID format.
FAQ
What format does UUID v4 follow?
The standard UUID v4 format is xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where 4 marks the version and y marks the variant.
Are UUID v4 values sequential?
No. UUID v4 values are random, so they are useful when you need identifiers without a central sequence.
When should I remove hyphens?
Remove hyphens only when a system requires compact identifiers. The hyphenated format is easier to read and more widely recognized.
Can I use UUIDs for database primary keys?
Yes, but random UUIDs can affect index locality in some databases. Use them when distributed generation matters more than sequential ordering.