uniku: ten type-safe ID strategies, each benchmarked fastest

ULIDs sort by creation time and stay shorter than a hyphenated UUID. Use them when the value will often appear in URLs, logs, or APIs.

import { ulid } from 'uniku/ulid'

const eventId = ulid()
// '01KXBK40T3EQW5BGTMQRX89PTA' (string)

Generated API reference

Public methods

Generate a ULID string or write its 16 canonical bytes into a buffer. ULIDs are URL-safe, carry a millisecond timestamp, and sort by creation time.

ulid

Generate a time-ordered ULID string.

ulid(): string

Generate a ULID with explicit options or write its 16 canonical bytes into a caller-owned buffer.

ulid<TBuf extends Uint8Array = Uint8Array>(options: UlidOptions | undefined, buf: TBuf, offset?: number): TBuf

Generate a ULID string with optional timestamp or random bytes.

ulid(options?: UlidOptions, buf?: undefined, offset?: number): string

UlidOptions

random?: 16 bytes of random data to use for ULID generation. Only the first 10 bytes are used.
Uint8Array
msecs?: Timestamp in milliseconds since Unix epoch. Defaults to Date.now().
number

Exampleulid()// => '01KXBK40T3EQW5BGTMQRX89PTA'

toBytes

Convert a ULID string to its canonical 16-byte representation.

toBytes(id: string): Uint8Array

Exampleulid.toBytes('01KXBK40T3EQW5BGTMQRX89PTA')// => Uint8Array [1, 159, 87, 50, 3, 67, 117, 248, 85, 195, 84, 190, 58, 132, 219, 74]

fromBytes

Convert 16 canonical ULID bytes to a ULID string.

fromBytes(bytes: Uint8Array): string

Exampleulid.fromBytes(Uint8Array.from([1, 159, 87, 50, 3, 67, 117, 248, 85, 195, 84, 190, 58, 132, 219, 74]))// => '01KXBK40T3EQW5BGTMQRX89PTA'

timestamp

Read the embedded Unix timestamp in milliseconds.

timestamp(id: string): number

Exampleulid.timestamp('01KXBK40T3EQW5BGTMQRX89PTA')// => 1783874323267

isValid

Return whether a value is a syntactically valid ULID string.

isValid(id: unknown): id is string

Exampleulid.isValid('01KXBK40T3EQW5BGTMQRX89PTA')// => true

NIL

The nil ULID (all zeros)

NIL: string

Exampleulid.NIL// => '00000000000000000000000000'

MAX

The max ULID (maximum valid value)

MAX: string

Exampleulid.MAX// => '7ZZZZZZZZZZZZZZZZZZZZZZZZZ'