Developer

UUID Generator & Validator

Create random (v4), time-ordered (v7) or timestamp (v1) UUIDs — one or hundreds at a time — and check whether any UUID is valid.

Generate UUIDs

Version

122 random bits from your browser's secure random generator. The usual choice.

Format

e.g. 550e8400-e29b-41d4-a716-446655440000

1–500 at a time.

Your UUIDs

Pick a version and press Generate

Validate a UUID

Check the format and see its version, variant and — for v1 and v7 — when it was created. Braces and urn:uuid: are fine.

  • v4, v7 and v1

    Random, time-sortable or classic timestamp UUIDs, all from your browser's secure random generator.

  • Bulk generation

    Up to 500 at once for seeding databases and test data. Copy them all or download a .txt file.

  • Validation

    Check any UUID or GUID and see its version, variant and — for v1 and v7 — when it was made.

Free online UUID generator

A UUID (universally unique identifier), also called a GUID, is a 128-bit ID written as 32 hex digits, like 550e8400-e29b-41d4-a716-446655440000. Anyone can generate one without asking a central server, and the chance of two random UUIDs ever clashing is so small it can be ignored. UUIDs are defined in RFC 9562, which replaced RFC 4122 in 2024.

Which version should I use?

  • v4 (random): 122 random bits. The default choice for record IDs, file names and request IDs.
  • v7 (time-ordered): the first 48 bits are the current time in milliseconds, the rest mostly random. New IDs sort after old ones, which keeps database indexes fast — a great fit for primary keys.
  • v1 (timestamp):the older time-based format. This tool uses a random node rather than your device's MAC address, so nothing about your machine leaks.
  • Nil UUID: all zeros (00000000-0000-0000-0000-000000000000), used as an “empty” placeholder.

Common uses

  • Database primary keys in PostgreSQL, MySQL or MongoDB
  • Request and correlation IDs in APIs and microservices
  • File, upload and document names that must never collide
  • Seeding test data for a project or assignment

Formats

The standard form is lowercase and hyphenated in groups of 8-4-4-4-12. Some systems store UUIDs without hyphens, and Windows tools often show GUIDs in uppercase — switch the format and every generated UUID updates.

Everything is generated on your device with the Web Crypto API. Treat UUIDs as identifiers, not secrets: v1 and v7 reveal when they were made, so use a password generator for anything that must stay private.

Private by design. Everything runs in your browser — nothing you enter is uploaded or stored by AISeekho.

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