Are ULIDs unique enough?

Yes for typical app use. They combine time with randomness to reduce collisions.

When should I prefer UUIDs?

Use UUIDs when standards or libraries expect them explicitly.

UUID/ULID Generator - Generate UUID v4 and ULID

UUID/ULID Generator

Create random UUID v4 and lexicographically sortable ULID identifiers.

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit label used for information in computer systems. We generate Version 4 UUIDs, which are completely random and have a collision probability so low it's effectively zero.

What is a ULID?

A ULID (Universally Unique Lexicographically Sortable Identifier) is an alternative to UUIDs. It is sortable by time (like a timestamp) but still unique. This makes it excellent for database keys where sorting matters.

Key Differences:

UUID v4: Completely random. Not sortable. Standard for most IDs.
ULID: Sortable by creation time. Shorter string representation (26 chars).

Output

Batch generate: 1

Generate UUIDs and ULIDs for Unique Identifiers

Create random UUIDs (v4) or time‑sortable ULIDs for database keys, test data, and distributed systems. ULIDs are lexicographically sortable, which helps with indexing and logs.

Choosing an ID Type

UUID v4: Simple, widely supported, good general default.
ULID: Sorts by time, base32 output, friendly for logs and URLs.

Guidance

Avoid guessable identifiers for sensitive resources.
Let databases generate IDs when possible to avoid collisions.