UUID Generator (v4)
Generate one or many version-4 UUIDs — random 128-bit identifiers used as primary keys, session IDs and request IDs. Everything is produced locally with the browser's cryptographic random number generator.
How to use
Set how many UUIDs you need (up to 100), pick formatting options, and press Generate. Each one is independent and, for practical purposes, guaranteed unique: a UUID v4 has 122 random bits, so collisions are astronomically unlikely even across billions of IDs.
Use “no hyphens” for systems that expect a bare 32-character hex string, and “UPPERCASE” for legacy databases or APIs that are case-sensitive about IDs. The standard lowercase, hyphenated form (8-4-4-4-12) is what almost every modern library expects by default.
FAQ
What is a UUID v4?
A 128-bit identifier where all bits except a few fixed version/variant bits are chosen at random. It doesn't encode any information about when or where it was created — unlike UUID v1, which embeds a timestamp and MAC address.
Can two generated UUIDs ever collide?
In theory yes, in practice no: with 122 random bits, you'd need to generate around 2.7 quintillion UUIDs before a 50% chance of one collision. No real-world system generates anywhere near that volume.
Is it safe to use this generator for production data?
Yes — generation happens entirely in your browser via the Web Crypto API. Nothing is sent to a server, so the values here are exactly as safe as ones generated by any backend library.
What's the difference between UUID and GUID?
None in practice — GUID is Microsoft's name for the same concept. Both refer to the same 128-bit identifier format standardized in RFC 4122.