Tool
UUID Generator
Generate RFC 9562 version 4 (random) or version 7 (time-ordered) UUIDs.
Try it
This tool runs entirely in your browser. Nothing you type or paste is sent anywhere.
Generated 2 version 4 UUID(s).
How it works
- Drew 16 random bytes.
- Set the version nibble to 4 and the RFC variant bits.
- Formatted the 16 bytes as 8-4-4-4-12 lowercase hexadecimal.
- Version 4 UUIDs are random; they carry no ordering information.
Usage
- Choose version 4 for purely random identifiers or version 7 for sortable, time-ordered ones.
- Choose how many identifiers to generate (1 to 100).
- Copy the results.
Examples
Two reproducible v4 UUIDs
{
"version": "v4",
"count": 2,
"seed": "example"
}Time-ordered v7
{
"version": "v7",
"count": 1,
"seed": "example",
"timestamp": 1735689600000
}Limitations
What a UUID actually guarantees
A UUID is an identifier, not a secret. Version 4 carries 122 random bits and version 7 carries a timestamp plus random bits; both are designed to be unique, not unguessable.
Frequently asked questions
- Which version should I use?
- Use v7 for new database keys because it sorts by creation time and reduces index fragmentation; use v4 when ordering does not matter.
- Are generated identifiers sent anywhere?
- No. Generation happens locally with the platform random source.