UUID / GUID Generator
UUID FAQ
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems.
What are UUID versions?
UUIDs have multiple versions: v1 (timestamp + MAC address), v4 (random), and v5 (namespace + name hashed). Each version serves different use cases.
Which UUID version should I use?
UUID v4 is the most common and is based on randomness. Use v1 for time-ordered IDs and v5 when you need deterministic UUIDs based on input.
Are UUIDs truly unique?
The probability of generating duplicate UUIDs is extremely low, especially with v4. They are considered practically unique for most applications.
Can UUIDs be guessed?
UUID v1 may reveal time and hardware info, making it predictable. UUID v4 is random and much harder to guess.
What’s the difference between UUID and GUID?
UUID and GUID are essentially the same. UUID is the official standard, while GUID is Microsoft’s implementation.
About UUIDs
UUIDs (Universally Unique Identifiers) are 128-bit values used to ensure global uniqueness across systems, databases, and applications. They are represented as 36-character strings containing hexadecimal digits and hyphens.
UUID v1 is generated using the current timestamp and MAC address, making it sequential but potentially exposing system information. UUID v4 uses random numbers, ensuring strong unpredictability and wide usage in APIs, databases, and distributed systems. UUID v5 is derived from a namespace and a name using SHA-1, making it deterministic and repeatable for the same inputs.
This tool allows you to generate UUIDs of different versions instantly in your browser. All operations are done locally for speed, privacy, and security.