UUID Generator
Generate UUID v4 unique identifiers. Cryptographically random and collision-resistant. Useful for database keys, API tokens, session IDs, and any application requiring unique identifiers.
Generated UUIDs
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. UUIDs are designed to be unique across both space and time, making them ideal for distributed systems where centralized coordination isn't possible.
UUID Versions
Version 4 (Random)Generated from random numbers. Most common. 122 random bits.
Version 1 (Timestamp)Based on timestamp and MAC address. Rarely used today.
Version 5 (Namespace)Generated from namespace + name using SHA-1 hash.
Frequently Asked Questions
How unique are UUID v4?The probability of collision is approximately 1 in 2^122, making them effectively unique for any practical purpose.
Can UUIDs be guessed?UUID v4 uses cryptographically secure random numbers, making them practically impossible to guess.
Where are UUIDs used?Database primary keys, API tokens, session identifiers, file names, and distributed system identifiers.