Remove tinyMCE from admin and replace with textarea
No need to reinvent the wheel – put your editor support back and tweak the settings: function wpse_199918_wp_editor_settings( $settings, $editor_id ) { if ( $editor_id === ‘content’ && get_current_screen()->post_type === ‘custom_post_type’ ) { $settings[‘tinymce’] = false; $settings[‘quicktags’] = false; $settings[‘media_buttons’] = false; } return $settings; } add_filter( ‘wp_editor_settings’, ‘wpse_199918_wp_editor_settings’, 10, 2 );