Using WordPress ‘allowed_redirect_hosts’ PHP filter

by

The allowed_redirect_hosts WordPress PHP filter allows you to modify the list of allowed hosts that your WordPress site can redirect to.

Usage

add_filter('allowed_redirect_hosts', 'my_custom_allowed_redirect_hosts', 10, 2);

function my_custom_allowed_redirect_hosts($hosts, $host) {
    // your custom code here

    return $hosts;
}

Parameters

  • $hosts (string[]): An array of allowed host names.
  • $host (string): The host name of the redirect destination; empty string if not set.

More information

See WordPress Developer Resources: allowed_redirect_hosts

Examples

Allow a custom domain for redirection

add_filter('allowed_redirect_hosts', 'allow_my_custom_domain', 10, 2);

function allow_my_custom_domain($hosts, $host) {
    $hosts[] = 'my-custom-domain.com';
    return $hosts;
}

Allow subdomains for a specific domain

add_filter('allowed_redirect_hosts', 'allow_subdomains', 10, 2);

function allow_subdomains($hosts, $host) {
    if (preg_match('/(.+)\.example\.com/', $host)) {
        $hosts[] = $host;
    }
    return $hosts;
}

Block a specific domain from redirection

add_filter('allowed_redirect_hosts', 'block_specific_domain', 10, 2);

function block_specific_domain($hosts, $host) {
    $blocked_domain = 'blocked-domain.com';

    if (($key = array_search($blocked_domain, $hosts)) !== false) {
        unset($hosts[$key]);
    }
    return $hosts;
}

Allow multiple custom domains for redirection

add_filter('allowed_redirect_hosts', 'allow_multiple_custom_domains', 10, 2);

function allow_multiple_custom_domains($hosts, $host) {
    $additional_hosts = ['custom-domain-1.com', 'custom-domain-2.com'];
    $hosts = array_merge($hosts, $additional_hosts);
    return $hosts;
}

Allow all subdomains of the current domain

add_filter('allowed_redirect_hosts', 'allow_all_subdomains', 10, 2);

function allow_all_subdomains($hosts, $host) {
    $current_domain = parse_url(get_site_url(), PHP_URL_HOST);

    if (preg_match('/(.+)\.' . preg_quote($current_domain) . '/', $host)) {
        $hosts[] = $host;
    }
    return $hosts;
}