Remove default WordPress image sizes

remove-default-image-sizes.php

<?php
/* ----------------------------------------------------------------------------
 * Remove default image sizes
 * ------------------------------------------------------------------------- */

function remove_default_image_sizes( $sizes ) {

	/* Default WordPress */
	unset( $sizes['thumbnail'] );       // Remove Thumbnail (150 x 150 hard cropped)
	unset( $sizes['medium'] );          // Remove Medium resolution (300 x 300 max height 300px)
	unset( $sizes['medium_large'] );    // Remove Medium Large (added in WP 4.4) resolution (768 x 0 infinite height)
	unset( $sizes['large'] );           // Remove Large resolution (1024 x 1024 max height 1024px)

	/* With WooCommerce */
	unset( $sizes[ 'shop_thumbnail' ]);  // Remove Shop thumbnail (180 x 180 hard cropped)
	unset( $sizes[ 'shop_catalog' ]);    // Remove Shop catalog (300 x 300 hard cropped)
	unset( $sizes[ 'shop_single' ]);     // Shop single (600 x 600 hard cropped)

	return $sizes;
}
add_filter( 'intermediate_image_sizes_advanced', 'remove_default_image_sizes' );