UUID Generator

Generate random v4 or time-ordered v7 UUIDs in bulk

About this tool

A UUID is a 128-bit identifier you can mint anywhere without asking a central service whether it is taken. Version 4 fills almost every bit at random; version 7 puts a millisecond timestamp in the leading bits, so v7 values sort chronologically and index far better as a database primary key.

This generator uses the browser's cryptographic random source, produces up to 500 values at a time, and can emit them uppercased, without hyphens or wrapped in braces for the systems that insist on it.

When to use it

  • Seeding test fixtures, sample payloads or webhook bodies with realistic ids
  • Choosing a primary key that will not collide across shards or offline clients
  • Generating a correlation or idempotency id for a request you are about to send
  • Producing a time-sortable id (v7) instead of the index-fragmenting random v4

Worked example

Input

Version 7 × 3

Output

0195a6c1-3f00-7c6b-9a2e-4d1f0b8c5e21
0195a6c1-3f01-7a4d-8f3c-6b90de2417aa
0195a6c1-3f01-7b19-b0d4-72c5a8e93f60

The three values share a leading timestamp because they were generated in the same millisecond, which is what makes v7 sort in creation order.

Frequently asked questions

Are these UUIDs random enough to use in production?

Yes. They come from crypto.getRandomValues(), the same cryptographically secure source the platform uses for keys, rather than Math.random().

Should I pick v4 or v7?

Use v7 when the id becomes a database key or is sorted by creation time, because its timestamp prefix keeps inserts at the end of the index. Use v4 when the id must leak nothing at all, including when it was created.

Is a UUID the same thing as a GUID?

Yes — GUID is Microsoft's name for the same 128-bit identifier. The brace-wrapped format this tool can emit is the one the .NET and COM tooling expects.

Related tools