UUID Generator

Generate UUIDs (v1, v4, v7, v8) in bulk, with format options and a validator. Cryptographically random by default.

Version
How many
1 UUID
  • 8d73dc58-a3d3-4cb7-b098-692e16e8c927

01 — Overview

How it works

Generate one UUID or a thousand, in whatever version you need. v4 is fully random (default), v7 is timestamp-sortable, v1 is timestamp-based with a node ID, v8 is custom. Format the output as lowercase, uppercase, Base64, or URN. Includes a validator that decodes a UUID into its parts.

02 — Use cases

When to use it

  1. 01

    Generate a primary key for a quick test row in your database

  2. 02

    Seed a fixture file with a thousand realistic IDs

  3. 03

    Get a timestamp-ordered UUID v7 to use as a sortable identifier

  4. 04

    Validate a UUID you pulled from a log and find out which version it is

03 — Examples

Real input, real output

Generate 1 × UUID v4

ex 01

5b1f2a8c-3e9d-4b1c-9f6e-1a2b3c4d5e6f

Random UUID, the default for new identifiers in most systems.

Generate 5 × UUID v7

ex 02

0192f3a1-..., 0192f3a1-..., 0192f3a1-..., 0192f3a1-..., 0192f3a1-...

Timestamp-sortable UUIDs. Newer UUIDs sort after older ones lexicographically.

Validate 5b1f2a8c-3e9d-4b1c-9f6e-1a2b3c4d5e6f

ex 03

Valid, version 4 (random)

Confirms the input is a well-formed UUID v4.

04 — FAQ

Frequently asked

v4 is 122 bits of randomness — collision-proof but unordered, which causes B-tree index fragmentation in databases. v7 prefixes 48 bits of millisecond timestamp before the random bits, so newer UUIDs sort after older ones. Use v7 when ordering matters.

05 — More

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