UUID Generator
Generate cryptographically random UUID v4 identifiers instantly.
A UUID (Universally Unique Identifier) is a 128-bit label standardised by RFC 4122. The canonical format is xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where 4 marks the version and y is one of 8, 9, a, b (the variant bits).
Version 4 UUIDs are randomly generated. With 122 bits of randomness, you would need to generate approximately 2.7 × 10¹⁸ UUIDs to have a 50% chance of a single collision — effectively impossible for any real-world use case.
Common uses: database primary keys, session tokens, correlation IDs, file names, distributed system identifiers.
About UUID Generator
UUID Generator creates cryptographically random Version 4 UUIDs (Universally Unique Identifiers) entirely in your browser using the native Web Crypto API. Generate 1 to 100 UUIDs at once, toggle uppercase/lowercase, and copy individual UUIDs or all of them at once. UUIDs are 128-bit identifiers with 122 bits of randomness — the probability of a collision is astronomically low. Nothing is sent to any server.