UUID v4 & Random ID Generator
Bulk-generate RFC 4122 v4 UUIDs, NanoIDs, and random numbers — cryptographically random.
About This Tool & Technical Logic
A UUID v4 is a 128-bit identifier with 122 bits of randomness — collision odds are so low that generating billions per year for centuries still makes accidental duplicates effectively impossible. That's why they're the default database key across the industry.
This generator uses crypto.getRandomValues() and supports bulk output, uppercase formatting, braces/URN styles, and NanoID (a shorter, URL-friendlier alternative with comparable collision resistance).
Set 122 random bits, fix version (4) and variant (10xx) nibbles per RFC 4122 §4.4.
How to Use — Step by Step
- 1
Pick a format
Standard lowercase hyphenated suits most systems; uppercase or braced styles cover legacy COM/.NET conventions.
- 2
Generate in bulk
Up to 500 per click for seeding test databases — every ID is guaranteed unique within the batch.
- 3
Copy as list or JSON
Output formats include newline lists and JSON arrays for direct paste into fixtures and seeds.
Frequently Asked Questions
Mathematically yes, practically no: you'd need to generate 2.7 quintillion v4 UUIDs for a 50% chance of one duplicate.