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ULID Generator

Generate Universally Unique Lexicographically Sortable Identifiers. A sortable alternative to UUIDs.

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Applications

Creating universally unique, sortable identifiers for database primary keys, distributed event logs, and resource IDs in microservices architectures where chronological ordering matters and central ID authority isn't feasible.

ULID (Universally Unique Lexicographically Sortable Identifier)

ULIDs encode a 48-bit millisecond-precision Unix timestamp in the first 10 characters using Crockford Base32, followed by 16 characters of random data (80 bits), producing a 26-character string. The timestamp prefix makes ULIDs lexicographically sortable, enabling efficient B-tree index inserts in databases.

Fun Fact: Crockford Base32 avoids I, L, O, and U to eliminate visual ambiguity, making ULIDs case-insensitive and more human-readable than hex encoding. ULIDs are also URL-safe and can be generated at up to 2^80 unique values per millisecond!

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