A Must-use plugin to filter active plugins in on a per-page basis.

plugin-filter.php

<?php
/**
 * @package active-plugins
 * @version 1.0
 *
 * Plugin Name: Active Plugins
 * Plugin URI: http://wordpress.org/extend/plugins/#
 * Description: This is a development plugin 
 * Author: Carlo Daniele
 * Version: 1.0
 * Author URI: https://carlodaniele.it/
 */

// shortcode to list active plugins 
add_shortcode( 'activeplugins', function(){
	
	$active_plugins = get_option( 'active_plugins' );
	$plugins = "";
	if( count( $active_plugins ) > 0 ){
		$plugins = "<ul>";
		foreach ( $active_plugins as $plugin ) {
			$plugins .= "<li>" . $plugin . "</li>";
		}
		$plugins .= "</ul>";
	}
	return $plugins;
});

$request_uri = parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH );

$is_admin = strpos( $request_uri, '/wp-admin/' );

if( false === $is_admin ){

	// filter active plugins
	add_filter( 'option_active_plugins', function( $plugins ){

		global $request_uri;

		$is_contact_page = strpos( $request_uri, '/contact/' );

		// change elements according to your needs
		$myplugins = array( 
			"contact-form-7/wp-contact-form-7.php", 
			"code-snippets/code-snippets.php",
			"query-monitor/query-monitor.php",
			"autoptimize/autoptimize.php" 
		);

		if( false === $is_contact_page ){
			$plugins = array_diff( $plugins, $myplugins );
		}

		return $plugins;

	} );
}

As it is today, I am finding the code snippet will indeed deactivate the chosen plugins but will never reactivate them. Accessing the correctly associated URL does not turn them back on. You have to go into the admin panel and reactivate the plug-in after removing this code.

I experienced a similar problem when I was developing a very similar plugin. The NextGEN Gallery plugin was updating the active_plugins option at shutdown. My workaround was to run this at shutdown before NextGEN ran its logic.

do_action( 'activate_plugin', __FILE__);

Has anyone been able to get this to work with in_category() or has_term()? I am trying to make a MU plugin that disables plugins one posts and pages in certain categories.

Has anyone been able to get this to work with in_category() or has_term()? I am trying to make a MU plugin that disables plugins one posts and pages in certain categories.

@ryanhollister I believe the plugins will already be loaded before those things are determined. Parsing the page URL might be a workaround for categories if your permalink settings include the category name.

how about to unload plugins for product page with WooCommerce?