---
id: options-subtitle
title: Subtitle Options
sidebar_label: Subtitle
---

Controls the top bar subtitle.

```js
const options = {
  topBar: {
    subtitle: {}
  }
};
```

### `text`

Subtitle text.

| Type   | Required | Platform |
| ------ | -------- | -------- |
| string | No       | Both     |

### `fontSize`

Subtitle fontSize. On Android this value is `sp`.

| Type   | Required | Platform |
| ------ | -------- | -------- |
| number | No       | Both     |

### `color`

Subtitle color.

| Type  | Required | Platform |
| ----- | -------- | -------- |
| Color | No       | Both     |

### `fontFamily`

Subtitle FontFamily.

| Type       | Required | Platform |
| ---------- | -------- | -------- |
| FontFamily | No       | Both     |

### `alignment`

`fill` will make the subtitle stretch and consume all available space in the TopBar while `center` will center the subtitle in the middle of the TopBar.

| Type                   | Required | Platform |
| ---------------------- | -------- | -------- |
| enum('center', 'fill') | No       | Both     |

### `testID`

Used to interact with the TopBar in e2e tests.

| Type   | Required | Platform |
| ------ | -------- | -------- |
| string | No       | Both     |