# Function: ulid()

> > **ulid**(): [`Arbitrary`](../classes/Arbitrary.md)\<`string`\>

# Function: ulid()

> **ulid**(): [`Arbitrary`](../classes/Arbitrary.md)\<`string`\>

Defined in: [packages/fast-check/src/arbitrary/ulid.ts:41](https://github.com/dubzzz/fast-check/blob/4663db899d411b24434189b8e560b5ecefc93f23/packages/fast-check/src/arbitrary/ulid.ts#L41)

For ulid

According to [ulid spec](https://github.com/ulid/spec)

No mixed case, only upper case digits (0-9A-Z except for: I,L,O,U)

## Returns

[`Arbitrary`](../classes/Arbitrary.md)\<`string`\>

## Remarks

Since 3.11.0