Generate secure, random Version 4 UUIDs (Universally Unique Identifiers) directly in your browser.
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. The probability of generating a duplicate UUID is so close to zero that it is negligible.
There are different versions of UUIDs. Version 4 is completely random (unlike v1 which is time-based). This makes it perfect for generating non-guessable IDs for database keys, session tokens, or file names.
A v4 UUID is a 128-bit identifier whose bits are almost entirely random, giving 122 bits of randomness. That makes accidental collisions effectively impossible in practice, which is why v4 is the default choice for database keys, request IDs and more.
A v4 UUID is generated with your browser's cryptographically secure random number generator, so it is unpredictable. It is fine as an unguessable token, though a purpose-built secret generator with more entropy is better for high-security use.
For any realistic volume, yes. The probability of generating two identical v4 UUIDs is negligible — you would need to generate billions before a collision became remotely likely.