How is a ULID different from a UUID?

A ULID starts with a timestamp, so ULIDs sort by creation time and are more index-friendly. A UUID v4 is fully random and sorts randomly. ULIDs are also shorter to read at 26 characters.

With 80 bits of randomness per millisecond, collisions are practically impossible for normal use.

Are ULIDs case sensitive?

No. Crockford Base32 is case-insensitive and avoids ambiguous characters like I, L, O and U.

Generators

ULID Generator

Generate sortable, unique ULIDs in bulk.

Free foreverRuns in your browserNo sign-up

How many

ULIDs are generated locally. Each one embeds the current time, so they sort in creation order.

About the ULID Generator

A ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character ID made of a 48-bit timestamp and 80 bits of randomness, encoded in Crockford Base32.

Because the timestamp comes first, ULIDs sort in the order they were created, which makes them handy as database keys where UUIDs would sort randomly.

This tool generates them locally using your browser's secure random generator.

Key features

Timestamp-prefixed, sortable IDs
Crockford Base32, URL-safe and case-insensitive
Bulk generation
Secure, local generation

How to use

1Choose how many ULIDs you need.
2Click Generate.
3Copy the results into your database or code.

Examples

Sortable ID

Produces a 26-character ULID whose leading characters encode the current time, so a list of them sorts chronologically.

Frequently asked questions

How is a ULID different from a UUID?: A ULID starts with a timestamp, so ULIDs sort by creation time and are more index-friendly. A UUID v4 is fully random and sorts randomly. ULIDs are also shorter to read at 26 characters.
Are ULIDs unique?: With 80 bits of randomness per millisecond, collisions are practically impossible for normal use.
Are ULIDs case sensitive?: No. Crockford Base32 is case-insensitive and avoids ambiguous characters like I, L, O and U.