UUID Generator (v4)
Generate cryptographically secure UUID v4 values in bulk using the Web Crypto API. Client-side only.
Generated UUIDs
What this UUID generator does
Generate random UUID v4 values using the Web Crypto API — the same source of randomness your browser uses for secure operations. No server, no seed, nothing stored. Generate one ID or thousands, with or without hyphens, in any case.
Why version 4
Version 4 UUIDs are fully random (122 bits of entropy). They are the standard choice when you need a unique identifier with no ordering or host information.
Uniqueness. Random UUIDs are not guaranteed unique in the mathematical sense, but the odds of a collision are negligible — billions of billions of IDs are needed before it becomes a realistic risk.
Format. A v4 UUID looks like
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where y is one of 8, 9, a or b. The 4 and y are the markers that identify it as version 4.