Default values

Setting default values in RVF is easy using the defaultValues option in the useForm hook.

const form = useForm({
  // ...validator and other options
  defaultValues: {
    firstName: "Jane",
    lastName: "Doe",
    email: "jane.doe@example.com",
  },
});

Type safety

For modern forms using a Standard Schema validator, it's required to set default values. The type of defaultValues is inferred from your schema.

The types of the form object returned by useForm (form.value(), form.setValue(), etc) are based around the inferred input type.

If you're using a legacy validator, the type of defaultValues is not inferred from your validator, and only from defaultValues.

const form = useForm({
  schema: z.object({
    name: z.string(),
  }),
  // Type inferred from schema above!
  defaultValues: {
    selectedOption: "",
  },
});

In some cases, a value that can occur while filling out the form won't be present in the schema. In this case you can widen the type by casting a field inside defaultValues.

const form = useForm({
  schema: z.object({
    selectedOption: z.string(),
  }),
  defaultValues: {
    // Widens the type of `selectedOption` to `string | null`
    selectedOption: null as string | null,
  },
});

Example

Form with default values

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