ULID Generator

A ULID is a 26-character Crockford Base32 identifier: the first 10 characters encode a 48-bit millisecond Unix timestamp, and the last 16 encode 80 bits of randomness. Sorting the values as plain strings reproduces creation order, and it's shorter and case-insensitive compared to a 36-character UUID.

Both aim for timestamp-based sortability. ULID came first, while UUID v7 became an official standard (RFC 9562) in 2024. Use v7 if standard compliance matters; stick with ULID if you're already using its ecosystem (libraries, DB column types).

Yes. The first 10 characters are a millisecond timestamp, so pasting a value into this tool's check field shows an approximate creation time right away. The remaining 16 characters are random and don't add precision.

It's an encoding using 32 characters — digits 0-9 and the letters minus the easily-confused I, L, O, and U. It's designed to reduce transcription errors when people copy values by hand, and it's case-insensitive, so upper- and lowercase represent the same value.

No. Every value is generated on the spot in your browser and is never sent to or stored on a server.