# FontSizeConfig

interface

The configuration of the font size feature. This option is used by the [`FontSizeEditing`](module_font_fontsize_fontsizeediting-FontSizeEditing.md) feature.

```typescript
ClassicEditor
	.create( {
		fontSize: ... // Font size feature configuration.
	} )
	.then( ... )
	.catch( ... );
```

See [all editor options](module_core_editor_editorconfig-EditorConfig.md).

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-font/src/fontconfig.ts#L285)

<a id="properties">

## Properties

<a id="member-options">

### `options?: Array<string | number | FontSizeOption>`

Available font size options. Expressed as predefined presets, numerical "pixel" values or the [`FontSizeOption`](module_font_fontconfig-FontSizeOption.md).

The default value is:

```typescript
const fontSizeConfig = {
	options: [
		'tiny',
		'small',
		'default',
		'big',
		'huge'
	]
};
```

It defines 4 sizes: **tiny**, **small**, **big**, and **huge**. These values will be rendered as `<span>` elements in the view. The **default** defines a text without the `fontSize` attribute.

Each `<span>` has the the `class` attribute set to the corresponding size name. For instance, this is what the **small** size looks like in the view:

```html
<span class="text-small">...</span>
```

As an alternative, the font size might be defined using numerical values (either as a `Number` or as a `String`):

```typescript
const fontSizeConfig = {
	options: [ 9, 10, 11, 12, 13, 14, 15 ]
};
```

Also, you can define a label in the dropdown for numerical values:

```typescript
const fontSizeConfig = {
	options: [
		{
			title: 'Small',
			model: '8px'
		},
		'default',
		{
		 	title: 'Big',
		 	model: '14px'
		}
	]
};
```

Font size can be applied using the command API. To do that, use the `'fontSize'` command and pass the desired font size as a `value`. For example, the following code will apply the `fontSize` attribute with the **tiny** value to the current selection:

```typescript
editor.execute( 'fontSize', { value: 'tiny' } );
```

Executing the `fontSize` command without value will remove the `fontSize` attribute from the current selection.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-font/src/fontconfig.ts#L350)

<a id="member-supportAllValues">

### `supportAllValues?: boolean`

By default the plugin removes any `font-size` value that does not match the plugin's configuration. It means that if you paste content with font sizes that the editor does not understand, the `font-size` attribute will be removed and the content will be displayed with the default size.

You can preserve pasted font size values by switching the `supportAllValues` option to `true`:

```typescript
const fontSizeConfig = {
	options: [ 9, 10, 11, 12, 'default', 14, 15 ],
	supportAllValues: true
};
```

**Note:** This option can only be used with numerical values as font size options.

With this configuration font sizes not specified in the editor configuration will not be removed when pasting the content.

[See source](https://github.com/ckeditor/ckeditor5/blob/master/packages/ckeditor5-font/src/fontconfig.ts#L370)

---

Full index of the CKEditor 5 API reference: [llms.txt](llms.txt)