ULID Anatomy
A ULID is a 128-bit identifier represented as a 26-character base32
string. Unlike UUIDs, they are lexicographically sortable.
01ARZ3NDEKTSV4RRFFQ69G5FAV
• First 10 chars: Timestamp (48 bits, precise to milliseconds, valid until 10889 AD)
• Last 16 chars: Randomness (80 bits CSPRNG)
ULID Anatomy
A ULID is a 128-bit identifier represented as a 26-character base32
string. Unlike UUIDs, they are lexicographically sortable.
01ARZ3NDEKTSV4RRFFQ69G5FAV
• First 10 chars: Timestamp (48 bits, precise to milliseconds, valid until 10889 AD)
• Last 16 chars: Randomness (80 bits CSPRNG)
ULID Generator
Instantly generate sortable ULIDs in bulk. Inspect the internal structure differentiating the timestamp and random components.
Use Cases
- Providing sortable primary keys for distributed databases
- Generating batch testing identifiers
Frequently Asked Questions
Why ULID over UUID?
ULIDs are lexicographically sortable, meaning they can be sorted chronologically without needing a separate created_at column.