UUID Generator
Generate random v4 UUIDs instantly. Bulk generate up to 100 UUIDs, toggle uppercase and hyphen formatting, and copy with one click.
Click Generate to create UUIDs.
Frequently Asked Questions
What is a UUID?
UUID stands for Universally Unique Identifier. It is a 128-bit identifier that is guaranteed to be unique across space and time. UUIDs are commonly used as primary keys in databases, session identifiers, and anywhere a unique reference is needed without a central authority.
What is the difference between UUID v1 and v4?
UUID v1 is generated using the current timestamp and the MAC address of the computer, making it partially predictable. UUID v4 is generated using random or pseudo-random numbers, making it completely unpredictable. This tool generates v4 UUIDs, which are the most commonly used type.
Are UUIDs truly unique?
While not mathematically impossible, the probability of generating a duplicate UUID v4 is astronomically small. You would need to generate about 2.71 quintillion UUIDs to have a 50% chance of a collision. For all practical purposes, UUIDs are unique.
What is the format of a UUID?
A standard UUID is a 128-bit value represented as 32 hexadecimal digits, displayed in 5 groups separated by hyphens in the format 8-4-4-4-12 (e.g., 550e8400-e29b-41d4-a716-446655440000). Without hyphens, it is simply 32 hex characters.
Is a GUID the same as a UUID?
GUID (Globally Unique Identifier) is Microsoft's implementation of the UUID standard. While the terms are often used interchangeably, GUIDs typically follow the same format as UUID v4. The main difference is terminology: UUID is the standard term, while GUID is specific to Microsoft technologies.