UUID Generator
Generate random UUID v4 identifiers. Bulk generate and copy with one click.
About UUIDs
UUID v4 (Universally Unique Identifier) is a 128-bit random identifier. The probability of generating a duplicate is astronomically low — you'd need to generate about 2.71 quintillion UUIDs to have a 50% chance of one collision. Generated using crypto.randomUUID() for cryptographic randomness.
Frequently Asked Questions
What is a UUID?▼
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. It follows the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. UUIDs are designed to be unique across all computers without a central authority.
What is UUID v4?▼
UUID v4 is a version of UUID that uses random or pseudo-random numbers. It's the most commonly used version. The 'v4' means 6 bits are fixed (4 for version, 2 for variant), and the remaining 122 bits are randomly generated, giving 5.3 × 10^36 possible UUIDs.
What is the difference between UUID and GUID?▼
UUID and GUID (Globally Unique Identifier) are essentially the same thing. Microsoft uses the term GUID, while the rest of the industry uses UUID. They follow the same RFC 4122 specification and are interchangeable.
Can two UUIDs be the same?▼
Theoretically yes, but practically no. The probability of generating duplicate UUID v4s is astronomically low — you would need to generate 1 billion UUIDs per second for about 85 years to have a 50% chance of a single collision.
Where are UUIDs used?▼
UUIDs are used as database primary keys, session identifiers, file names, API tokens, distributed system IDs, and tracking identifiers. They're preferred over auto-incrementing integers when you need globally unique IDs without central coordination.