Loona UUID Generator - Random Version 4 UUIDs, Bulk up to 100
Database rows, API resources, file names and test data all need IDs that will not collide. A version 4 UUID carries 122 bits of randomness - for practical purposes, no two will ever match. This generator uses crypto-grade randomness (not Math.random), so the IDs are safe for real systems.
How to use the UUID Generator
- Choose how many UUIDs you need - from 1 to 100.
- Optionally switch to UPPERCASE or turn hyphens off.
- Click Generate, then copy all or download them as a text file.
How it works
A UUID is a 128-bit identifier written as 32 hexadecimal digits in five groups: 8-4-4-4-12. In version 4, almost every bit is random; two fixed positions mark the version (the "4" at the start of the third group) and the variant (the 8, 9, a or b at the start of the fourth group). This tool prefers the browser's native crypto.randomUUID() and falls back to building one from crypto.getRandomValues() bytes with the version and variant bits set by hand - both sources are cryptographically secure.
Worked example
A typical result looks like 3f6b2a90-4c1d-4e8f-9a2b-5c7d1e0f8a44 - note the 4 starting the third group and the 9 starting the fourth. Generate 100 at once and each one is independently random, ready to paste into a seed script.
Frequently Asked Questions
Is this UUID generator free?
Yes - free, no sign-up, generate as often as you like.
What is a version 4 UUID?
A UUID in which nearly all bits are random. It is the most widely used UUID type for database keys, resource IDs and idempotency keys.
Could two generated UUIDs ever be identical?
In theory yes, in practice no - with 122 random bits you would need to generate billions per second for centuries before a collision became likely.
Why do people remove the hyphens or use uppercase?
Some systems store UUIDs as 32 plain hex characters, and some legacy databases use uppercase. The value is identical; only the formatting differs.
Are the UUIDs generated on a server?
No - they are generated by your browser's cryptographic functions on your own device.
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