UUID Generator
Generate one or many cryptographically random UUID v4 identifiers.
How it works
UUIDs (Universally Unique Identifiers) let systems assign IDs without needing a central authority to coordinate and avoid collisions -- a database, a distributed system, or a test fixture can each generate UUIDs independently and never collide in practice. This generator produces RFC 4122 version 4 UUIDs, the most common variant, using your browser's cryptographically secure random number generator (crypto.randomUUID()).
Generate a single UUID or up to 100 at once -- useful for seeding test data, generating primary keys before an insert, or creating unique session and tracking identifiers. Each one follows the standard 8-4-4-4-12 hexadecimal format.
Everything happens locally in your browser; no UUIDs are logged or transmitted anywhere.
Frequently asked questions
Are these UUIDs guaranteed unique?
UUID v4 uses 122 random bits, making collisions astronomically unlikely in practice -- you'd need to generate billions before a collision becomes a realistic concern.
What's the difference between UUID and GUID?
They're effectively the same concept -- GUID (Globally Unique Identifier) is Microsoft's term, UUID is the general/standard term, and both follow the same format.
Can I generate more than 100 at once?
This tool caps at 100 per generation to keep the interface responsive. For bulk generation, a script calling crypto.randomUUID() in a loop is more practical.
Are UUID v4 values sortable?
No -- v4 UUIDs are fully random, not time-ordered. If you need sortable unique IDs, look into ULID or UUID v7, which embed a timestamp.