PrivTab

UUID Generator

Make unique IDs for databases, files and APIs, one at a time or up to 100,000 at once, and see what an existing UUID says about itself.

Runs in your browser · No uploads

Kind

Version 4 is 122 random bits from your browser's secure random generator: the usual choice. Version 7 starts with the time, so new IDs sort after older ones, which keeps database indexes fast.

Inspect a UUID

  • Nothing leaves your device
  • No server-imposed size limits
  • No sign-up, no watermark
  • Free

How to generate UUIDs

  1. Choose version 4 (random) or version 7 (time-ordered) and how many.
  2. Pick the format: uppercase, without hyphens, braces, a JSON array or a quoted list.
  3. Copy or download them.

Version 4 or version 7?

  • Version 4: 122 random bits. The usual choice, with no information about when or where it was made.
  • Version 7 (RFC 9562): starts with the time in milliseconds, so new IDs sort after old ones. That keeps database indexes compact and fast. UUIDs made in the same millisecond still sort in order.

Inspect a UUID

Paste any UUID to see its version and variant, and for time-based versions (1, 6 and 7) when it was created.

Frequently asked questions

Can two UUIDs ever be the same?

In theory, but the chance is so small it never matters in practice: you would need to make billions per second for many years. They come from your browser's cryptographically secure random generator.

Are the UUIDs stored anywhere?

No. They are made in your browser and disappear when you close the page.