Generate UUID v4 in bulk using a secure random source (Web Crypto API). Supports uppercase, removing hyphens, and wrapping in braces
A UUID (Universally Unique Identifier) is a 128-bit identifier designed to be unique across the world. It is standardized in RFC 4122 / RFC 9562. Version 4 is the variant generated from random numbers: 122 bits are random, and the remaining bits are fixed to indicate the version (4) and the variant. UUID v4 is widely used wherever you need non-colliding IDs, such as database primary keys and session IDs.
A v4 UUID holds 122 random bits, giving roughly 5.3 x 10^36 possible combinations. As long as a good random source is used, the probability of a collision within any realistic usage is negligibly small. For example, even after generating a billion UUIDs the chance of a collision is estimated to be extremely low. Note, however, that it is not exactly zero, only vanishingly small in probability.
Yes. This tool uses the browser Web Crypto API (crypto.randomUUID or crypto.getRandomValues) to generate UUID v4 from a cryptographically secure random source. It does not use the predictable Math.random(). All generation happens entirely within your browser, and the results are never sent to or stored on a server.