Generate secure RFC 4122 version 4 UUIDs for development and testing.

UUID v4

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What Is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value used to identify records without relying on an auto-incrementing database ID. In most apps, UUID v4 is popular because it is random and collision-resistant for practical use.

When Should You Use UUIDs?

  • When data is created in multiple services and merged later.
  • When you do not want to expose sequential IDs in APIs or URLs.
  • When offline or client-side creation is needed before sync.

Quick Best Practices

  • Keep UUIDs lowercase for consistency across systems.
  • Store as native UUID type in databases when supported.
  • Treat UUIDs as identifiers, not secrets or authentication tokens.