📘 Developer Guide

UUID v4 Identifiers: When to Use Random IDs in Databases and APIs

A practical guide to UUID v4 identifiers, database records, public API IDs and distributed systems.

Jun 29, 2026 1 min read DevToolPlace

What is a UUID?

A UUID is a universally unique identifier used to label records, resources and events. Version 4 UUIDs are generated from random data and are common in distributed systems.

Why Developers Use UUIDs

  • Create public identifiers that are hard to guess
  • Generate IDs across multiple services
  • Avoid coordination between distributed systems
  • Create reliable test data
  • Identify API resources consistently

UUIDs vs Auto-Increment IDs

Auto-increment IDs are simple and efficient, but they reveal sequence information. UUIDs are larger, but they are useful when IDs are generated outside a single database or exposed publicly.

Best Practices

Use UUIDs when distributed generation, public resource IDs or hard-to-guess identifiers are useful. For high-volume database tables, review indexing strategy because UUIDs are larger than integer IDs.

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