[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [local‑first/Owner](https://evolu.dev/docs/api-reference/common/local-first/Owner) › ownerIdToOwnerIdBytes

```ts
function ownerIdToOwnerIdBytes(
  ownerId: string & Brand<"Id"> & Brand<"OwnerId">,
): Uint8Array<ArrayBufferLike> &
  Brand<"Length16"> &
  Brand<"IdBytes"> &
  Brand<"OwnerIdBytes">;
```

Defined in: [packages/common/src/local-first/Owner.ts:98](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Owner.ts#L98)

Converts [OwnerId](https://evolu.dev/docs/api-reference/common/local-first/Owner/variables/OwnerId) to [OwnerIdBytes](https://evolu.dev/docs/api-reference/common/local-first/Owner/variables/OwnerIdBytes).