How to use the uuid generator
- Pick v4 (random) or v7 (time-ordered) and how many you need.
- Click Generate. A fresh batch appears instantly.
- Toggle uppercase, hyphens and braces to match the target format.
- Copy one, copy all, or download them as a text file.
Features
- UUID v4 from crypto.randomUUID / crypto.getRandomValues
- UUID v7 with a millisecond timestamp prefix that sorts chronologically
- Bulk generation up to 1,000 at a time
- Uppercase, hyphen-less and braced formats for .NET, registry keys and SQL
- No network requests: nothing is logged or reused
v4 or v7?
Version 4 UUIDs are 122 bits of randomness. They're the default choice for identifiers that must be unguessable and independent of time. Version 7, standardised in RFC 9562, starts with a 48-bit Unix millisecond timestamp followed by random bits. Because they sort by creation time, v7 values make excellent database primary keys: inserts append to the index instead of scattering across it, which keeps B-tree indexes compact.
Both are globally unique for practical purposes. The chance of two v4 UUIDs colliding is so small that you'd need to generate billions per second for centuries to expect one.
Formats
The canonical form is 32 lowercase hex digits in 8-4-4-4-12 groups. Some systems want uppercase (older Microsoft tooling), no hyphens (compact database columns) or braces (COM and registry GUIDs). The output is the same value in each case.