> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vturb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Update subtitle

> Toggle subtitles and style the caption text; the track file itself is read-only.

The subtitle group turns captions on, exposes the toggle to the viewer, and
styles the caption text. The track itself — the file with the actual captions —
is read-only here.

This is a [merge-patch](/guides/merge-patch): send only the keys you want to
change and everything else keeps its stored value.

## Style the captions

<CodeGroup>
  ```bash cURL theme={null}
  curl -X PATCH https://api.vturb.com/v1/videos/{id} \
    -H "Authorization: Bearer vt_..." \
    -H "Content-Type: application/json" \
    -d '{ "subtitle": { "enabled": true, "style": { "font_size": "18px", "color": "#FFFFFF", "text_align": "center" } } }'
  ```

  ```json Body theme={null}
  {
    "subtitle": {
      "enabled": true,
      "style": {
        "font_size": "18px",
        "color": "#FFFFFF",
        "text_align": "center"
      }
    }
  }
  ```
</CodeGroup>

## The keys

| Key                      | Type    | Writes                                  |
| ------------------------ | ------- | --------------------------------------- |
| `enabled`                | boolean | Turns subtitles on or off               |
| `control`                | boolean | Shows the subtitle toggle on the player |
| `style.font_size`        | string  | Caption font size, e.g. `18px`          |
| `style.color`            | string  | Caption text color                      |
| `style.background_color` | string  | Color behind the caption text           |
| `style.text_align`       | string  | `left`, `center` or `right`             |
| `style.show_by_default`  | boolean | Start with captions visible             |

`track` (`name`, `url`) and the layout leaves `style.bottom` and
`style.max_width` appear on `GET` but are read-only — patches to them are
ignored.