Setting home and siteurl dynamically in Wordpress

Use wp_config.php or functions.php to set home and siteurl dynamically.

Hard-coded constants

In wp-config.php.:

define('WP_SITEURL', 'http://<your.domain.here>/');
define('WP_HOME', 'http://<your.domain.here>/'); 

If these two constants are set the _config_wp_home and _config_wp_siteurl will be used by WordPress to overwrite the settings in the database.

Custom filters

Alternatively, you can dynamically set your home and siteurl options by attaching your own callbacks to option_home and option_site filters in functions.php of your theme.

function my_filter_option_siteurl( $siteurl ) {
  // filter $siteurl here   
  return $siteurl; 
}; 
             
// add the filter 
add_filter( 'option_siteurl', 'my_filter_option_siteurl');

function my_filter_option_home( $home ) {
  // filter $home here 
  return $home; 
}; 
             
// add the filter 
add_filter( 'option_home', 'my_filter_option_home', 10, 1 );