Guides
When to Use UUID vs ULID
UUID and ULID both solve the same broad problem: generating identifiers without relying on a central sequence. The main difference is that ULID is designed to stay sortable by time, while UUID v4 is mostly about random uniqueness.
Published March 22, 2026 · Updated March 22, 2026
When UUID Is The Simpler Choice
UUID v4 is a common default when you need a widely recognized random identifier for APIs, databases, events, or general application records. It is familiar, broadly supported, and easy to drop into many existing systems.
That makes it a strong default when you care more about compatibility than about sort order.
When ULID Helps More
ULID becomes attractive when you want identifiers that stay lexicographically sortable by time while still being unique. That can help with logs, ordered records, and workflows where insertion order matters during inspection.
It is often useful for developer tooling, event-style records, and systems where roughly time-ordered IDs make debugging easier.
How To Choose Quickly
If you just need a standard random ID, UUID v4 is usually the safer default. If readable ordering and time-sortable behavior matter, ULID is often the better fit.
That is why a combined generator is useful: you can create either format quickly depending on the workflow in front of you.