Display Image File Size in WordPress Media Folder

display-image-file-size-wordpress.php

//* Get file size for all of your items in the Media library
//* URL: https://wordpress.stackexchange.com/questions/237131/display-image-file-size-in-media-library

add_filter( 'manage_upload_columns', 'wpse_237131_add_column_file_size' );
add_action( 'manage_media_custom_column', 'wpse_237131_column_file_size', 10, 2 );

function wpse_237131_add_column_file_size( $columns ) { // Create the column
    $columns['filesize'] = 'File Size';
    return $columns;
}
function wpse_237131_column_file_size( $column_name, $media_item ) { // Display the file size
    if ( 'filesize' != $column_name || !wp_attachment_is_image( $media_item ) ) {
      return;
    }
    $filesize = filesize( get_attached_file( $media_item ) );
    $filesize = size_format($filesize, 2);
    echo $filesize;
}