Theme Supports

WordPress supplies hooks that allow a developer to de/activate certain features of the block editor. Within the child theme starter, certain theme supports have been active, and other deactivated. Within the child theme, the developer can un/comment the feature for the specific project within the theme-support.php file.

The WordPress Block Developer handbook provides an overview of Theme Supports and all the options available up to the latest version of WordPress.

Default active theme support

align-wide
Allow blocks such as the image block have the possibility to define a “wide” or “full” alignment.
disable-custom-colors
Disable the color palette offered to blocks that allows the user to select a custom color different from the editor or theme default colors.
disable-custom-font-sizes
Disable the ability to set custom font sizes.
disable-custom-gradients
Disable the ability to set a custom gradient.
editor-font-sizes
The block provides a default set of font sizes, but a theme can overwrite it and provide its own.
editor-styles
Enqueue and load CSS on the editor screen. For the classic editor, this was the only function needed to add style to the editor. For the new block editor, you also need to use add_editor_style. This feature is automatically enabled for block themes, and does not need to be included during theme setup.
html5
This feature is automatically enabled for block themes, and does not need to be included during theme setup.
post-thumbnails
Post thumbnails and featured images allow your users to choose an image to represent their post. This feature is automatically enabled for block themes, and does not need to be included during theme setup.
responsive-embeds
To make the content resize and keep its aspect ratio, the <body> element needs the wp-embed-responsive class. This is not set by default, and requires the theme to opt in to the responsive-embeds feature.
wp-block-styles

Default removed theme support

automatic-feed-links
Enables post and comment RSS feeds by default. This feature is automatically enabled for block themes, and does not need to be included during theme setup.
block-templates
core-block-patterns
WordPress comes with a number of block patterns built-in, themes can opt-out of the bundled patterns and provide their own set.
custom-background
custom-header
custom-line-height
Some blocks like paragraph and headings support customizing the line height.
widgets-block-editor
Disabled Widget Block Editor

Below are some optional settings to activate

admin-bar
custom-logo
customize-selective-refresh-widgets
custom-spacing
Some blocks can have padding controls. This is off by default.
custom-units
In addition to pixels, users can use other units to define sizes, paddings… The available units are: px, em, rem, vh, vw.
dark-editor-style
featured-content
menus
post-formats
Post formats allow users to format their posts in different ways.
starter-content
title-tag
widgets

Additional settings available in future versions of WordPress

appearance-tools
WP 6.5 Enable the WP Global Styles settings.
block-template-parts
WP 6.1 Enable Block Based Template parts, allowing administrators to edit parts of the site using blocks. This is off by default.
border
WP 6.3 Enable all border settings.
disable-layout-styles
WP 6.1 By enabling the following code, themes commit to providing their own structural styling, as using this feature will result in core blocks displaying incorrectly in both the editor and site frontend.
link-color

These settings cannot be activated within the `setup_theme_supported_features` function, due to additional configurations settings

Note: these can be set in theme.json which is usually preferred.

custom_units
editor-color-palette
editor-gradient-presets
editor-font-sizes

Options that can be switched via `theme.json`