Add Attachment ID to WordPress Media Library Details Panel

add-attachment-id-to-wp-media-library.php

<?php
/**
 * Add Attachment ID to WordPress Media Library Details Panel.
 *
 * This snippet adds a new, non-editable field to the "Attachment Details"
 * panel in the WordPress Media Library, displaying the media file's unique ID.
 *
 * HOW TO USE:
 * 1. The BEST way: Use a code snippets plugin like WPCode.
 * 2. The ADVANCED way: Add it to a custom functionality plugin.
 * 3. The RISKY way (not recommended): Add it to your active theme's functions.php file.
 */

/**
 * Adds the Attachment ID field to the attachment edit form.
 *
 * @param array   $form_fields An array of attachment form fields.
 * @param WP_Post $post        The attachment WP_Post object.
 * @return array The modified array of form fields.
 */
function add_attachment_id_to_media_details( $form_fields, $post ) {

    // Create the new field
    $form_fields['attachment_id'] = array(
        'label' => 'Attachment ID',
        'input' => 'html',
        'html'  => '<span>' . $post->ID . '</span>',
        'helps' => 'The unique ID for this media file.'
    );

    return $form_fields;
}

// Hook the function into the 'attachment_fields_to_edit' filter.
add_filter( 'attachment_fields_to_edit', 'add_attachment_id_to_media_details', 10, 2 );