This plugin hasn’t been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.



Domainer lets you route custom domain names to specific sites on your Multisite installation. That’s it.

Domain Options

Each domain has 4 options you set:

  1. The target site; pick from a list of existing sites on your network.
  2. A type, choose from one of 3 flavours:
    • Primary: sites with a primary domain will have their URLs redirected to them.
    • Redirect: these domains will always redirect to the primary domain, or the original failing that.
    • Alias: these won’t redirect to the primary, so they’re bad for SEO but can be useful for certain setups.
  3. A www rule, choose from one of 3 options:
    • Always: always redirect to the domain with www at the front.
    • Never: always redirect to the domain without www at the front.
    • Auto: allow the domain to function with or without www, usually bad for SEO.

Content Rewriting

In order to reduce redirects while navigating the site, Domainer will replaced all instances of the site’s original domain name on the pages to that of the primary domain, or currently requested alias domain. This will not affect email addresses however; any filters on the content will only replace instances starting with a double slash so as to match URLs.

If you find instances of the domain not being replaced, such as in content filtered by 3rd party plugins, you can patch it with this function:

add_filter( 'my_filter', 'domainer_rewrite_url' );

The function can also take a domain or array of domains to replace, as well as a specific domain to replace with.


  1. Upload the contents of domainer.tar.gz to your /wp-content/plugins/ directory.
  2. Activate the plugin through the ‘Plugins’ menu in WordPress.
  3. Assuming the system is unable to take care of it automatically:
    1. Copy the sunrise.php file to /wp-content/.
    2. Add define('SUNRISE', true); to your wp-config.php file, anywhere above the ABSPATH line.
  4. Start adding domains under Network Admin > Domains.


February 3, 2021
Same as Bryan above: installed as instructed but got immediately error for the hole wp-installation. Had to delete sunrise-file and reload old wp-config to get back on track.
July 12, 2020 3 replies
This plugin was not tested with my version…ehm the current WP and I should listen to this warning. Plugin ruined wp-config.php as I did try to click on “give it a shot” Domainer cannot function until you complete the following: Copy sunrise.php file in Domainer’s plugin folder to your site’s wp-content directory. Add define(‘SUNRISE’, true); to your site’s wp-config.php file. Domainer may be able to do this itself. Click here to give it a shot. Every page running on same Multisite WP Installation was down in no time and there was no access to WP Backoffice. There has been a critical error on your website. Please check your site admin email inbox for instructions. Very very very bad idea.
June 8, 2020
I was struggling to make Polylang domain mapping work for my multisite installation for days and booom. I found this plug-in and worked immediately with the option to add alias domain names to my primary website. It canceled the error I was getting with Polylang because domain names was not configured in the multisite installation. I had an url like /wp-signup.php?new= showing up when trying to access the alias for Polylang. Hope it will be maintained because WordPress doesn’t support aliases natively. And I didn’t find other alternatives for my installation. Thank you very much !
June 13, 2020
I needed to route custom domain names to specific sites on my Multisite installation. That’s it. Domainer lets me route custom domain names to specific sites on my Multisite installation. That’s it. It does exactly what I needed, does it transparently, and does it well.
Read all 12 reviews

Contributors & Developers

“Domainer” is open source software. The following people have contributed to this plugin.


“Domainer” has been translated into 1 locale. Thank you to the translators for their contributions.

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Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.


Details on each release can be found on the GitHub releases page for this project.


Improved UX and error handling of Sunrise install process.


Network Only now. Fixed session handling that was causing loopback requests to fail.

Fixed subdirectory rewrites, ironed out install process.


Fixed rewrite handling on subdirectory style network setups.


Fixed handling of alias domains, improved security of remote login/logout.


Remote login capabilities, blog switching and site selecting fixes.


Fixed bug with deleting domains and certain redirect URLs.


Initial public release.