Update jquery version

Question

I run WordPress version 4.7.2. and it uses jQuery version 1.12. I need to update this version to a higher one. I replaced it with a new version before, but when I upgrade WordPress core it is replaced with 1.12 again. How can I change the version of jQuery that WordPress uses permanently?

Answer 1

Warning: You shouldn't replace core jQuery version, especially in the admin panel. Since many WordPress core functionality may depend on the version. Also, other plugin may depend on the jQuery version added in the core.

If you are sure that you want to change the core jQuery version, in that case you may add the following CODE in your active theme's functions.php file (even better if you create a plugin for this):

function replace_core_jquery_version() {
    wp_deregister_script( 'jquery' );
    // Change the URL if you want to load a local copy of jQuery from your own server.
    wp_register_script( 'jquery', "https://code.jquery.com/jquery-3.1.1.min.js", array(), '3.1.1' );
}
add_action( 'wp_enqueue_scripts', 'replace_core_jquery_version' );

This will replace core jQuery version and instead load version 3.1.1 from Google's server.

Also, although not recommended, you may use the following additional line of CODE to replace the jQuery version in wp-admin as well:

add_action( 'admin_enqueue_scripts', 'replace_core_jquery_version' );

This way, even after updating WordPress, you'll have the version of jQuery as you want.

A slightly better function:

The replace_core_jquery_version function above also removes jquery-migrate script added by WordPress core. This is reasonable, because the newest version of jQuery will not work properly with an older version of jquery-migrate. However, you can include a newer version of jquery-migrate as well. In that case, use the following function instead:

function replace_core_jquery_version() {
    wp_deregister_script( 'jquery-core' );
    wp_register_script( 'jquery-core', "https://code.jquery.com/jquery-3.1.1.min.js", array(), '3.1.1' );
    wp_deregister_script( 'jquery-migrate' );
    wp_register_script( 'jquery-migrate', "https://code.jquery.com/jquery-migrate-3.0.0.min.js", array(), '3.0.0' );
}

Answer 2

I have developed a plugin for this specific problem. The plugin doesn't mess with WordPress jQuery as it is only loaded in the front-end. See: jQuery Manager for WordPress

Why yet another jQuery Updater / Manager / Developer / Debugging tool?

Because none of the developer tools lets you select a specific version of jQuery and/or jQuery Migrate. Providing both the production and the minified version. See features below!

✅ Only executed in the front-end, doesn't interfere with WordPress admin/backend and WP customizer (for compatibility reasons) See: https://core.trac.wordpress.org/ticket/45130 and https://core.trac.wordpress.org/ticket/37110

✅ Turn on/off jQuery and/or jQuery Migrate

✅ Activate a specific version of jQuery and/or jQuery Migrate

And much more! The code is open source, so you could study it, learn from it and contribute.

Almost everybody uses the incorrect handle

WordPress actually uses the jquery-core handle, not jquery:

https://github.com/WordPress/WordPress/blob/91da29d9afaa664eb84e1261ebb916b18a362aa9/wp-includes/script-loader.php#L226

// jQuery
$scripts->add( 'jquery', false, array( 'jquery-core', 'jquery-migrate' ), '1.12.4' );
$scripts->add( 'jquery-core', '/wp-includes/js/jquery/jquery.js', array(), '1.12.4' );
$scripts->add( 'jquery-migrate', "/wp-includes/js/jquery/jquery-migrate$suffix.js", array(), '1.4.1' );

The jquery handle is just an alias to load jquery-core with jquery-migrate

See more info about aliases: wp_register_script multiple identifiers?

The correct way to do it

In my example below I use the official jQuery CDN at https://code.jquery.com I also use script_loader_tag so that I could add some CDN attributes.
You could use the following code:

// Front-end not excuted in the wp admin and the wp customizer (for compatibility reasons)
// See: https://core.trac.wordpress.org/ticket/45130 and https://core.trac.wordpress.org/ticket/37110
function wp_jquery_manager_plugin_front_end_scripts() {
    $wp_admin = is_admin();
    $wp_customizer = is_customize_preview();

    // jQuery
    if ( $wp_admin || $wp_customizer ) {
        // echo 'We are in the WP Admin or in the WP Customizer';
        return;
    }
    else {
        // Deregister WP core jQuery, see https://github.com/Remzi1993/wp-jquery-manager/issues/2 and https://github.com/WordPress/WordPress/blob/91da29d9afaa664eb84e1261ebb916b18a362aa9/wp-includes/script-loader.php#L226
        wp_deregister_script( 'jquery' ); // the jquery handle is just an alias to load jquery-core with jquery-migrate
        // Deregister WP jQuery
        wp_deregister_script( 'jquery-core' );
        // Deregister WP jQuery Migrate
        wp_deregister_script( 'jquery-migrate' );

        // Register jQuery in the head
        wp_register_script( 'jquery-core', 'https://code.jquery.com/jquery-3.3.1.min.js', array(), null, false );

        /**
         * Register jquery using jquery-core as a dependency, so other scripts could use the jquery handle
         * see https://wordpress.stackexchange.com/questions/283828/wp-register-script-multiple-identifiers
         * We first register the script and afther that we enqueue it, see why:
         * https://wordpress.stackexchange.com/questions/82490/when-should-i-use-wp-register-script-with-wp-enqueue-script-vs-just-wp-enque
         * https://stackoverflow.com/questions/39653993/what-is-diffrence-between-wp-enqueue-script-and-wp-register-script
         */
        wp_register_script( 'jquery', false, array( 'jquery-core' ), null, false );
        wp_enqueue_script( 'jquery' );
    }
}
add_action( 'wp_enqueue_scripts', 'wp_jquery_manager_plugin_front_end_scripts' );


function add_jquery_attributes( $tag, $handle ) {
    if ( 'jquery-core' === $handle ) {
        return str_replace( "type='text/javascript'", "type='text/javascript' integrity='sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8=' crossorigin='anonymous'", $tag );
    }
    return $tag;
}
add_filter( 'script_loader_tag', 'add_jquery_attributes', 10, 2 );