[](https://travis-ci.org/ulid/javascript) [](https://codecov.io/gh/ulid/javascript) [](https://www.npmjs.com/package/ulid) # THIS IS A FORK This package was forked from the actively supported & stable [ulid](https://github.com/ulid/javascript) library. The fork was created to improve compatibility in older browsers. # Universally Unique Lexicographically Sortable Identifier UUID can be suboptimal for many uses-cases because: - It isn't the most character efficient way of encoding 128 bits of randomness - UUID v1/v2 is impractical in many environments, as it requires access to a unique, stable MAC address - UUID v3/v5 requires a unique seed and produces randomly distributed IDs, which can cause fragmentation in many data structures - UUID v4 provides no other information than randomness which can cause fragmentation in many data structures Instead, herein is proposed ULID: - 128-bit compatibility with UUID - 1.21e+24 unique ULIDs per millisecond - Lexicographically sortable! - Canonically encoded as a 26 character string, as opposed to the 36 character UUID - Uses Crockford's base32 for better efficiency and readability (5 bits per character) - Case insensitive - No special characters (URL safe) - Monotonic sort order (correctly detects and handles the same millisecond)