I have a client that wants images to automatically be centered. This used to be possible with the image_default_align option for the old editor. Is there a simple way to change the default attributes for core blocks?

  • Gutenberg already have a align center option that appears on toolbar. You can add your editor styles via hook for some custom styling. Mar 11, 2019 at 21:19
  • Thanks @MehmoodAhmad I know the center options is there. My clients wants center to be the default for the image block. I would like to change this default attribute.
    – Nate
    Mar 13, 2019 at 1:41
  • I think it can be achievable via Block Filters (developer.wordpress.org/block-editor/developers/filters/…), but I'm not sure. Still working on this myself. Nov 16, 2019 at 17:08

1 Answer 1


As it was mentioned in comments it is possible with Block Filters. Below is the code that allowes images to be automatically centered when inserted.

wp.hooks.addFilter( 'blocks.registerBlockType', 'misha/img', ( settings, name ) => {
    // so we check block name here if it is image we change attributes
    if( 'core/image' === name ) {

        return lodash.assign( {}, settings, {
            attributes: lodash.assign( {}, settings.attributes, { 
                align: {
                    type: 'string', 
                    default: 'center'
            } )
        } )

  return settings

This code can be used in any JS file enqueued with enqueue_block_editor_assets, the code snippet I took from this guide https://rudrastyh.com/gutenberg/change-default-blocks-with-block-filters.html

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