Convert WordPress image to base64 by attach_id

convert-wp-image-to-base64.php

<?php
function tidaweb_image_url_to_base64( $attach_id )
{
    // get image src -> $image_info[0]
    $image_info = wp_get_attachment_image_src( $attach_id, 'full' );
    $image_file = file_get_contents( $image_info[0] );

    // get filename from url
    $filename = basename( get_attached_file( $attach_id ) );
    $image_file_type = wp_check_filetype( $filename );

    return 'data:image/'.$image_file_type['ext'].';base64,'.base64_encode( $image_file );
}