Redirect mobile users in Wordpress

readme.md

You can use this function to redirect a mobile user to a different homepage in Wordpress. In practice you would probably want to use a more robust user agent sniffer than the is_mobile() function shown here, such as Mobile Detect.

This code assumes you are using a static page with an ID of 1 for the homepage. If you are using the blog index for your homepage, replace !is_page(1) with !is_home().

If you wanted to not redirect but fetch a different page, you should be able to modify the query_vars on $query, but I haven't tried that.

functions.php

<?php

function is_mobile() {
    $is_mobile = (bool)preg_match( '#\b(ip(hone|od)|android\b.+\bmobile|'.
                                   'opera m(ob|in)i|windows (phone|ce)|blackberry|s(ymbian'.
                                   '|eries60|amsung)|p(alm|rofile/midp|laystation portable'.
                                   ')|nokia|fennec|htc[\-_]|up\.browser|[1-4][0-9]{2}x[1-4]'.
                                   '[0-9]{2})\b#i', $_SERVER['HTTP_USER_AGENT'] );
    return $is_mobile;
}

function mobile_redirect( $query ) {
    if ( !is_main_query() || !is_page(1) || !is_mobile() ) {
        return;
    }

    $mobile_homepage_id = 2;
    wp_redirect( get_permalink( $mobile_homepage_id ) );
    exit;
}
add_filter( 'pre_get_posts', 'mobile_redirect' );