Online Tool Store
UUID Generator
Generate cryptographically secure version 4 UUIDs one at a time or in bulk, with optional uppercase and hyphen formatting, then copy the full list at once. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Every UUID is generated fresh in your browser using cryptographically secure randomness.
How the UUID generator works
- Set how many UUIDs you need and any formatting options.
- Each one is generated with your browser's built-in cryptographically secure random number generator.
- Copy the full list to your clipboard with one click.
The method
A version 4 UUID is a 128-bit value where 6 bits are fixed to mark the version and variant, and the remaining 122 bits are filled with cryptographically secure random data, formatted as 32 hex digits grouped by hyphens.
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (y is 8, 9, a, or b)
FAQ
What version of UUID does this generate?
Version 4 (random) UUIDs, generated with the browser's crypto.randomUUID() API, which uses a cryptographically secure random number generator.
How unlikely is a collision?
A version 4 UUID has 122 random bits. You would need to generate roughly a billion UUIDs per second for about 85 years before a 50% chance of a single collision.
Can I generate UUIDs without hyphens or in uppercase?
Yes. Toggle "Include hyphens" and "Uppercase" - both formats are still valid UUIDs, just formatted differently for the system you're pasting them into.
Are the generated UUIDs sent anywhere?
No. Every UUID is generated locally in your browser and never leaves the page.
How we compare
| Feature | Online Tool Store | uuidgenerator.net | Node.js crypto CLI |
|---|---|---|---|
| Bulk generation up to 1,000 at once | ✓ | ✓ | Scripted only |
| No install required | ✓ | ✓ | ✗ |
| No ads on the page | ✓ | ✗ | ✓ |
For quick, ad-free UUIDs in bulk without opening a terminal, UUID Generator is the fastest option.