What is ULID?
ULID (Universally Unique Lexicographically Sortable Identifier) is a sortable, unique identifier proposed by Alizain Feerasta in 2016. It combines a timestamp and a random number generator to generate a 32-bit identifier that is suitable for identifying data entities and events in distributed systems.
Why use ULID?
ULID has some advantages over UUID:
- Sortable: Since ULID is generated based on the timestamp, it can be sorted by timestamp, which is very useful for indexing and querying databases. Also, since ULID uses a timestamp-based prefix, the first 12 characters can be used to determine the timestamp, making debugging and data management easier.
- Readability: ULID consists of 32 characters, of which the first 12 characters are generated by the timestamp. The timestamp can be determined by these 12 characters. This is useful for debugging and data management.
- Low collision rate: ULID has a very low collision rate because it uses a timestamp-based prefix and a random number generator to generate the ULID, making the generated ULID globally unique.
- Short and lightweight: ULID has only 32 characters, while UUID has 36 characters, which means that ULID is shorter, lighter, and better suited for use in distributed systems.
- Security: ULID uses a random number generator based on CSPRNG to generate the random number part, making it more secure and less susceptible to attacks.