UUID Generator

This tool generates random version 4 UUIDs, also known as GUIDs, instantly and for free, as many at a time as you need. A UUID, or universally unique identifier, is a 128-bit value written as 32 hexadecimal characters in five groups separated by hyphens, such as the familiar 8-4-4-4-12 pattern. Developers reach for UUIDs whenever they need an identifier that is practically guaranteed to be unique without coordinating with a central server: primary keys in databases, request and transaction IDs, file and object names, session tokens and message identifiers. The version 4 variant is built almost entirely from random bits, which is why the chance of two ever colliding is so vanishingly small that they can be generated independently on different machines with confidence. This generator uses your browser's cryptographically strong random source where available, so the values are suitable for real use rather than just demonstration. You choose how many UUIDs you want and they appear immediately, one per line, ready to copy into your code, database seed, configuration file or test fixtures. A regenerate button gives you a fresh batch whenever you need one. Everything happens locally in your browser, so the identifiers are never sent anywhere, which matters when they are used as keys or tokens. A quick note on format: version 4 UUIDs always have the digit four at the start of the third group and one of eight, nine, a or b at the start of the fourth, a useful way to recognise them. Generate one for a quick test or a hundred to seed a dataset.

Version 4 (random) UUIDs, generated locally in your browser using a cryptographically strong source where available. Up to 50 at a time.