The settings.border property in theme.json gives you control over the global border settings for blocks in WordPress. It’s important to note that this lets you configure the available settings in the user interface, not the border styles themselves.

Each of the border settings maps to a control at the individual block level and in the Styles interface for blocks, letting you curate which controls are available to your theme users:

Border settings

WordPress supports four border settings that you can configure via the settings.border property in theme.json. Each of them allows you to enable or disable a specific border feature and accepts a boolean (true or false) value:

• color: Enables/Disables the border-color picker.
• radius: Enables/Disables the border-radius control.
• style: Enables/Disables the border-style selector (users have the option of solid, dashed, or dotted).
• <strong>width</strong>: Enables/Disables the border-width input.

By default, all border properties are set to false, as shown in this example theme.json code:

{
	"version": 2,
	"settings": {
		"border": {
			"color": false,
			"radius": false,
			"style": false,
			"width": false
		}
	}
}