Block Support

Block supports are used to enable or disable block features such as alignments, colors and spacing. These are features that are commonly shared across many block types. During block development, developers can register blocks supports in the block.json file (Example).

Read the official documentation for block supports.

• Blocks can have partial or full support for a feature. For example, a block may support border color, but not border radius.
• Many block supports have a matching control in the editor, but not all. An example of a support that does not have an interface is the aria-label.

To learn which WordPress core block has which block support, you can use the select list further down on this page.

How to disable block supports

Theme and plugin developers can use different methods to disable block supports in core blocks or third-party blocks:

• Using theme.json
• With PHP, by filtering theme.json or block meta data
• With JavaScript, filtering theme.jon data with wp.hooks.addFilter and blockEditor.useSetting.before

Read more in the official how-to guide about curating the editor experience. This page also includes code examples.

Adding block supports

It is not possible to use theme.json to add new block supports. If you are planning to try to add a new block support to an existing block using a filter, test it carefully, because for full support, you may also need to adjust the block’s markup, CSS, edit and save function.

For example, if you would try to enable color support for the navigation link (the inner block of the navigation block), you would see the controls in the block settings sidebar, but only some colors would work.

Experimental block supports

Experimental block supports are subject to change and are prefixed with “__experimental”.

This can mean that the feature is new or needs to be tested before it can be considered stable. It can also mean that there are planned changes, or that there are known bugs or difficulties with the implementation. – Though it can be said that features have been known to remain experimental only because there are no Gutenberg developers available that have the time to change the state of the feature.

As a block developer you may use these but be aware that the specifics of the feature might change.

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