UUID Generator
Generate UUID v4 (RFC 4122) instantly. Up to 1,000 IDs per click. Optional uppercase and no-hyphen formats.
- 100% local · no upload
Frequently asked questions
What is UUID v4?
Universally Unique Identifier version 4 — a 128-bit ID generated using cryptographically secure random bytes. RFC 4122 standard. Format: 8-4-4-4-12 hex characters separated by hyphens.
Is collision possible?
In theory yes, in practice no. UUID v4 has 122 bits of randomness. To have a 50% chance of collision, you'd need to generate ~2.71 quintillion UUIDs.
When to use UUID instead of auto-increment?
Distributed systems (no central coordinator), client-side ID generation, security through obscurity (URLs without sequential IDs leaking count info), database sharding.
What's the difference between UUID v4 and v7?
v4 is fully random. v7 (newer) is timestamp-prefixed — better for database indexing because IDs sort chronologically. Most systems still use v4.
Can I use without hyphens?
Yes — toggle the option. Some systems (URL-friendly IDs, MongoDB ObjectIds-style) prefer no hyphens. The 32-char hex form is unambiguous.