UUID Generator
Generate random UUIDs (v4) instantly. Click a UUID to copy it.
Universally Unique Identifiers are 128-bit values used as database primary keys, session tokens, and distributed system identifiers. This generator creates version 4 (random) UUIDs using cryptographic randomness, conforming to RFC 4122. Generate single IDs or batches of thousands instantly.
Generating...
How to Generate UUIDs
- Click "Generate" — a new random UUID v4 appears instantly.
- Set quantity — generate up to 100 UUIDs at once for bulk needs.
- Choose format — lowercase, UPPERCASE, with {braces}, or without dashes.
- Click to copy — click any UUID to copy it, or use "Copy All" for bulk.
Frequently Asked Questions
What is a UUID? ▼
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in systems. Version 4 UUIDs are randomly generated and follow the format
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where x is a random hex digit and y is one of 8, 9, a, or b.UUID vs GUID — what's the difference? ▼
They are the same thing. UUID is the standard term used in the IETF RFC 4122 specification. GUID (Globally Unique Identifier) is Microsoft's name for the same concept, commonly seen in .NET and Windows environments.
Are these UUIDs truly unique? ▼
For all practical purposes, yes. UUID v4 uses 122 random bits, giving 5.3 × 10^36 possible values. The probability of a collision is infinitesimally small. This tool uses the cryptographically secure
crypto.getRandomValues() API.Where are UUIDs used? ▼
UUIDs are used as database primary keys, API identifiers, session tokens, file names, distributed system IDs, and anywhere a unique identifier is needed without a central authority.