UUID v4 Generator
Generate cryptographically random UUID v4 identifiers instantly. UUID v4 uses random data for all significant bits, making collisions statistically impossible. These are the most commonly used UUIDs in modern applications — databases, APIs, session tokens, and distributed systems.
Frequently Asked Questions
›What is UUID v4?
UUID v4 is a universally unique identifier where all significant bits (122 of 128) are randomly generated. The version nibble is set to 4 and the variant bits are set per RFC 4122. This makes each UUID virtually guaranteed to be unique without any coordination.
›How random is UUID v4?
UUID v4 uses crypto.getRandomValues() in the browser, which provides cryptographically secure random numbers. With 122 random bits, you'd need to generate 2.71 quintillion UUIDs to have a 50% chance of a single collision.
›Should I use UUID v4 as a primary key?
UUID v4 works well as a primary key in distributed systems where coordination is difficult. The downside is poor index locality (random ordering). If you need sortable IDs, consider ULIDs or UUID v7 instead.