UUID Generator
Generate v4 (random) or v1 (timestamp) UUIDs instantly. Bulk generation, format options, and UUID validator — all in your browser.
Validate a UUID
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier standardized by RFC 4122, represented as 32 hexadecimal digits in the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. UUIDs are designed to be unique across space and time without requiring a central authority.
What is the difference between UUID v4 and v1?
UUID v4 is generated using random numbers and is the most common type. UUID v1 is generated using the current timestamp and a node identifier (usually a MAC address substitute), making it sortable by creation time but potentially revealing timing information.
Are the generated UUIDs truly unique?
UUID v4 uses 122 bits of randomness from the browser's cryptographically secure random number generator. The probability of generating a duplicate UUID v4 is approximately 1 in 5.3×10^36, which is astronomically low for any practical application.
What is the difference between UUID and GUID?
UUID and GUID (Globally Unique Identifier) refer to the same concept. GUID is the term used by Microsoft and Windows technologies, while UUID is the standard term used elsewhere. They follow the same RFC 4122 format and are interchangeable.
Can I use these UUIDs in production?
Yes. This tool uses the browser's built-in crypto.randomUUID() function for v4 UUIDs, which is cryptographically secure and follows RFC 4122. The generated UUIDs are suitable for use as database primary keys, API identifiers, session tokens, and other production use cases.