About this tool
About ULID Generator
Generate ULIDs online without installing a package or sending input to a server. The tool creates one identifier or a batch of up to 500 and lets you choose uppercase or lowercase output.
What is a ULID?
ULID stands for Universally Unique Lexicographically Sortable Identifier. Each value contains a 48-bit Unix timestamp in milliseconds and 80 bits of randomness, encoded into 26 Crockford Base32 characters. The format avoids easily confused characters such as I, L, O and U.
Generate ULIDs in bulk
Choose a quantity, generate the list and copy one result or the complete batch. Downloading TXT is useful for fixtures, database imports and local development. Generation uses secure random values supplied by the current browser.
ULID compared with UUID
ULIDs are compact, case-insensitive and sortable by their timestamp portion. UUID v4 is widely supported and entirely random, while UUID v7 also includes a Unix timestamp but keeps the familiar UUID layout.
For Windows APIs or configuration fields that explicitly request a GUID, use the GUID Generator instead. A ULID's 26-character Base32 representation is not a drop-in replacement for a hexadecimal GUID.
Privacy and uniqueness
Identifiers are generated locally and are not sent to zer.ai. Random identifiers are designed to make collisions extremely unlikely, but no generator can provide an absolute uniqueness guarantee. Systems that require strict uniqueness should still enforce a unique database constraint.