ULID generator
Generate ULIDs (lexicographically sortable unique identifiers), a UUID alternative.
🔒 100% client-side — no data sent
Generate chronologically sortable ULID identifiers, a modern alternative to UUIDs for your databases and primary keys. Generation uses crypto.getRandomValues, 100% in the browser: nothing is sent to a server.
What is it for?
- ▸ Create primary keys sortable by creation time.
- ▸ Replace a UUID v4 with an orderable identifier.
- ▸ Generate IDs for timestamped logs or events.
- ▸ Improve database index performance.
FAQ
What's the difference between ULID and UUID?
A ULID embeds a timestamp, making it chronologically sortable, unlike a fully random UUID v4.
Is a ULID unique?
Yes: 48 bits of timestamp and 80 bits of randomness make collisions extremely unlikely.
How many characters is a ULID?
26 characters in Crockford Base32, without ambiguous characters like I, L, O or U.
Can I use a ULID as a primary key?
Yes, its chronological order improves index locality compared to a random UUID.