Change homepage based on cookie?

Yes it is possible / feasible.

Custom code of course.

Use the ‘init’ hook to set the cookie, if not set.

Use the ‘template-redirect’ hook to inspect the cookie if set and redirect if landing on ‘real’ home to ‘temporary home’

@fullworks alright, so that all makes sense, but are redirects the ideal way to this? If I understand what you’re saying, I would do something like

if ( is_front_page() ) {
        wp_redirect( home_url( '/mens/' ) );

So “home” icons would still take them to url.com, but they would still be re-directed to url.com/mens.

Is there a way to, without redirecting, changing the url of home_url?

The redirect happens before the page is loaded on so it is not really a redirect in that sense. i.e. it will just happen not be a load / reload ( don’t forget the exit after wp_redirect – also i’d use wp_safe_redirect )

Thats the way I’d do it ( and do in a similar way my 404 redirect plugin for instance )

You can’t update the options table for site url and that will impact every one.

You cant filter options_siteurl or options_home as that will impact many things that you could not control and would be a mess.

The alternative is for you code the logic at theme level, for instance in the header where it displays the logo with a home link apply the cookie lookup and in the menu apply logic too – there is a plugin that allows using shortcodes in menu items so you could write a simple shortcode to check the cookie.

Alternatively, if you are so inclined, you could examine the cookie in htaccess
e.g.

RewriteEngine On
RewriteCond %{HTTP_COOKIE} !cookie_name=specific_value; [NC]
RewriteRule ...