ULID Generator & Inspector

A ULID (Universally Unique Lexicographically Sortable Identifier) is a 128-bit identifier written as 26 Crockford Base32 characters. The first 10 characters encode a 48-bit Unix timestamp in milliseconds and the last 16 characters hold 80 random bits, so ULIDs sort by creation time as plain strings while staying practically collision-free.

1. 1.Choose Generate, set how many ULIDs you need and whether the timestamp is now or a custom date-time.
2. 2.Turn on Monotonic when the batch must stay sorted inside one millisecond.
3. 3.Select Generate ULIDs, then copy single values, copy all, or download them as text, JSON, CSV, SQL or code.
4. 4.Choose Inspect and paste one ULID per line to validate them and read their timestamps.

Both are 128-bit identifiers. A ULID is shorter as text (26 characters instead of 36), sorts by creation time, and uses an alphabet without ambiguous letters. A random UUID v4 reveals nothing about when it was made. If your database column expects UUIDs, the inspector shows each ULID in UUID layout; UUID v7 is the standardized time-ordered alternative.

A valid ULID has exactly 26 characters from 0-9 and A-Z without I, L, O and U, and its first character is 0-7 so the timestamp fits in 48 bits. Input is case-insensitive and normalized to uppercase; I, L and O are rejected rather than read as 1 and 0. Generation uses crypto.getRandomValues and runs only in your browser; nothing is stored or sent. The timestamp is visible to anyone who sees a ULID, so do not use ULIDs where creation time must stay private or as unguessable tokens.