UUID Generator
IDs come from your browser's cryptographic random source and are never sent anywhere; they exist only on this page.
How it works
仕組みStamp out fresh UUIDs or short random IDs on demand, using your browser’s cryptographic random source. Nothing is fetched from a server and nothing you generate leaves this page. Choose standard UUID v4 (the 36-character 8-4-4-4-12 format used everywhere from databases to APIs) or a compact 12-character ID drawn from a 62-character alphabet, nanoid-style. Generate one, five, or ten at a time; every row has its own copy button, plus copy-all for the batch. Because the IDs are minted on your own device, they’re as unpredictable as your browser’s crypto allows.
A v4 UUID contains 122 random bits, so the chance of any collision is astronomically small: you’d need to generate about a billion UUIDs per second for decades before it becomes likely. For everyday keys, filenames, and request IDs, treat them as unique. The 12-character short IDs have fewer bits (about 71), which is still ample for most app-level use.
Almost all of it is random. Two spots are fixed by the standard: the first digit of the third group is always 4 (the version), and the first digit of the fourth group is 8, 9, a, or b (the variant). Everything else comes straight from the random source, which is why v4 UUIDs carry no timestamp or machine information.
Short IDs shine where humans see the value: URLs, filenames, promo codes, and log lines, since 12 characters are easier to read and share than 36. Full UUIDs are the safer default for database keys and anything interoperating with other systems, because the format is universally recognised. Both here are generated with crypto-grade randomness.