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How to enable Multi-Site option in WordPress 3.0

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WordPress 3.0 is when the big merge happens. The core of WPMU is incorporated in WordPress which means that you can now run multiple blogs from one installation of WordPress. This new feature is being called Network or Multi-site option. By default this feature is disabled. If you want to use this option in your WordPress, then you would have to enable it.

To enable this feature, simply open your wp-config.php file located in your WordPress root folder. Then add the following line anywhere in the file:

define('WP_ALLOW_MULTISITE', true);

Once you have done that, you should be able to access the network page from Tools » Network

WordPress Multi-site Option

Now, you no longer need to install multiple copies of WordPress because you can run multiple blogs from one installation. By default, you would only be allowed to run other blogs as a subdomain. To use other domains for blogs, you can use a Domain Mapping plugin.

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Editorial Staff at WPBeginner is a team of WordPress experts led by Syed Balkhi with over 16 years of experience in WordPress, Web Hosting, eCommerce, SEO, and Marketing. Started in 2009, WPBeginner is now the largest free WordPress resource site in the industry and is often referred to as the Wikipedia for WordPress.

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93 CommentsLeave a Reply

  1. Syed Balkhi says

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  2. mohadese esmaeeli says

    Hello! Is it better to have a WordPress network, or should we use the subdomains and subdirectories feature to launch side websites?
    In a WordPress network, the database is unified, and this may lead to crashes or database heaviness. What is your opinion? Which one is better?

    • WPBeginner Support says

      It would heavily depend on your specific use case for what would be best to use. If you are concerned about your database size then you would want to create individual sub-sites so each has their own database.


  3. Wayne Curran says

    Thanks for this info about enabling multi site.

    I have a problem though. I can’t install or upgrade anything. It keeps asking for ftp details. My wordpress is running on a synology NAS.

    • WPBeginner Support says

      @Wayne this problem usually occurs when WordPress is unable to write files on the server. It happens when PHP is running under mod_php or CGI as the user instead of the user that owns WordPress files. You can ask your hosting provider for support. Meanwhile you can also add your FTP credentials in wp-config.php file so that you don’t have to enter them each time.

      define( 'FTP_USER', 'username' );
      define( 'FTP_PASS', 'password' );
      define( 'FTP_HOST', '' );


      • Wayne Curran says

        Thanks for the reply.

        I think I need to add some more info.

        I installed wordpress on my Synology NAS via the package installer, so it’s installed locally on my NAS at home. The site isn’t hosted externally at all. Completely local. (it can be accessed from the web via a synology domain name)

        I’m currently only experimenting with building my sites. I need 3 sites hence why I need the multisite option. Without this option, I’m unable to experiment with all my sites. I can only play with one at a time.

        Anyhow, I should have also added initally that when I enter the ftp login details, they don’t work. I’ve racked my brains to try and work out what ftp details it could be after but none of them work.

        Are then specific login details for as you mentioned ‘mod_php or CGI’. I don’t even know what that means :-)

        • Wayne Curran says


          I’ve reinstalled from scratch. All working ok now.

          But, a new question.

          In the general settings, 2 fields are missing. WordPress address and site address.

          Any thoughts?

  4. Nimitz says

    Hi, it is possible that users has a blog on my wpmu then they can have their own domain name? same like on that any blog can upgrade to their own domain name?

  5. Alexander says

    Would you provide a step by step guide for creating a multi-site setup on local machine using Xampp on Windows 8.

  6. Yevgen says

    It seems that Domain Mapping plugin is unsupported anymore. Are there any alternatives? Is it possible to setup domains manually using functions.php?


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