How to Enable Multisite in WordPress

This video screencast is a quick tutorial for how to set up WordPress 3.0 in multisite mode. The WordPress codex has written instructions if you want to use those as well.


Update the wp-config.php file

You will need to add this line of code to your wp-config.php to make the multisite function accessible:

define('WP_ALLOW_MULTISITE', true);


WordPress codex documentation for using multisite:

How to map top level domains in multisite:

About Devin

I am a developer based in Austin, Texas. I run a little theme shop called DevPress and help manage a WooCommerce shop with Universal Yums. Find me on twitter @devinsays.

114 Responses

  1. Seagoing

    Hi, Thanks for vid-tut on network options in latest WP 3 Alpha
    I’ve recently (today) installed this, and updated it using Dashboard -> Updates but under tools i have DO NOT have the Network option to which you refer.

    Is there something to enable, during install perhaps, for this option to show?


  2. Danny G Smith

    Strange, I ran a co on that site, and have the alpha code, but I still don’t get Tools -> Network. I wonder if they are in the process of factoring the code, and something has gone wrong? I wouldn’t discount the possibility that I did something wrong.

  3. Seagoing

    Many thanks for pointing out how to enable Multisites on WP 3 Alpha by adding…

    define(‘WP_ALLOW_MULTISITE’, true);

    …to the file wp-config.php

    HOWEVER, having included the above line in my wp-config.php file I still do NOT get a Tools -> Network option! Does this have to be included AT INSTALL time?

  4. Seagoing

    OK – as a followup, the correct define statement that should go into wp-config.php to enable mutisites is…

    define(‘WP_ENABLE_MULTISITE’, true);

    Hope that helps

  5. Dan

    Actually according to the trac link above it is:

    define(‘WP_ALLOW_MULTISITE’, true);

    Also be careful when copying the code from here. I did it and it messed up the single quotes.

    WP_ALLOW_MULTISITE works :-) .

  6. RKM

    Great overview, thanks for taking the time to include screenshots, etc!

    Strange, the alpha/beta forums say to use: define(‘WP_ENABLE_MULTISITE’, true);

    I guess this is wrong; want to make sure people are aware of the difference.

    On a separate note, is there an option in v3.0 to allow domain-mapping? For example, rather than using *sub-domains* or *sub-directories* using domains as we did with domain-mapper? For example: and goes to and

    Thanks again for the great info!

  7. RKM

    @Devin- Thank you for the link. I was hoping this would now be native to v3 — but at least we have a definitive answer.

    I’m off to try a fresh v3 install w/Domain Mapping .51 now. Will report back.

  8. RKM

    @Devin –
    Setup v3.0-alpha, added Domain Mapping Plugin (as well as Login Lockdown) and they both work great. v3.0-alpha is much more intuitive than MU, IMHO.

    Here’s a quick tutorial on WP3 Domain Mapping (very similar to 2.x Domain Mapping, but some locations/etc have changed — and sunrise variable definition is not a commented part of the default wp-config for v3):

    add domain_mapping.php to \wp-content\plugins
    add sunrise.php to \wp-content

    add the following line to wp-config.php (or uncomment if it exists)
    define( ‘SUNRISE’, ‘on’ );

    go to Plugins > Network Activate
    go to Super Admin > Domain Mapping > set IP

    Setup domain mapping for a specific site:
    Super Admin > Sites > (choose site) > Backend
    (verify you’re now under the dashboard of that specific site)
    Tools > Domain Mapping > (set domain to use, choose Primary)

  9. Hi Andrea

    I tried enabling multisites on a new install and I’m getting errors:Fatal error: Call to undefined function get_blog_details() in /home/webtemp1/public_html/ on line 98

    WP is in a subfolder

  10. Nice screencast. This feature will make WP a bit like WP MU :). I don’t think it’s useful for personal blog, but maybe in some case of multi-author, it’s good to be used.

  11. Olaf

    Hi Devin,

    great video.

    This is just for your information, bluehost does allow wildcard subdomains or at least I have been able to create these. When you are in your cpanel and go to create a subdomain, if you add the * as the subdomain, it should create wildcard subdomains for you. Now I don’t know if this is something that was enabled on their part, by error or if they are now allowing it, as they still state that they don’t allow it in their knowledgebase. Also I don’t know if you need to have a dedicated ip for this to work, but it does work.

  12. Olaf,
    Interesting idea. I tested it out on my Bluehost account (with dedicated IP) and I can verify that this works. I also called Bluehost support and asked what the deal with this was. The support representative was unable to set up a subdomain using only the star character, strange??? The main reason I called support was to see to if the solution that you outlined was something that they supported, or a neat little unsupported work-around. I was instructed that this is not a practice that should be relied upon due to the fact that it is not officially supported and may change in the future. The representative than informed me that MU should work if all subdomains are created manually, which may be cumbersome to some uses, but fortunately will work fine for me.

  13. RKM

    For all of you who have issues with using wildcard hostname resolution, you can find very inexpensive VPS servers on networks just as good (or better) than what you’re using, for nearly the same price.

    The provider will setup everything you need, *including* a dashboard if you don’t want to get your hands dirty in Linux. On the other hand, if you are comfortable with the Linux side, it’s a simple entry in the httpd.conf file, which is on by default, that will support unlimited hosts, unlimited domains, etc.

    A VPS is so much more liberating than limiting yourself to your hosting providers rules/configuration.

  14. Hey Devin,

    VERY helpful video – thanks a lot for posting it. I’ve managed to get my existing site migrated 100% successfully from WP to WPMU but it seems that this isn’t necessary anymore with WP 3.0 coming out soon-ish.

    Is WP being merged into WPMU or is it the other way around? Any advantages to using WPMU over WP 3.0?

    Thanks again!

  15. Awesome post thanks – we’re testing this out at the moment too.

    @Miriam Schwab – I’m wondering the same thing. Would be awesome to manage multiple websites from the one install but still give access for users on individual sites the ability to log in and add/edit content etc… any news if this is possible?

  16. Chris, do you mean that you can’t edit the content for subsites from the main login? That’s what I’m hoping will be possible: managing content for all subsites (and the main site) from one control panel.

  17. @Miriam: Yes, you can (as confirmed by Devin, too). I have a user account called ‘admin’ that I use for changing stuff on the main site but a user called ‘chris’ that I use for creating the content … there’s no technical reason for doing it that way other than having the articles as having ‘chris’ as the author. Regardless, the ‘admin’ user can post content on any of the sites.

    In the WPMU control panel you can modify the list of users that are ‘Site Admins’ so that you could have a user called miriam that can do the same stuff that admin can.

  18. Mark Johnson

    Devin, just installed beta2 of WordPress 3.0 and used your instructions to enable Network, However, there is a section (Server Address) on the Create a Network of WordPress Sites page that has me stalled:

    We recommend you change your siteurl to “” before enabling the network feature. It will still be possible to visit your site using the www prefix with an address like “” but any links will not have the www prefix.

    Where do I change siteurl? In Settings? (it won’t let me, reverts it to In the wp-config.php file? FYI, I’m using subdirectories, not subdomains; have mod_rewrite activated via .htaccess on my 1&1 server. I’m also migrating from Movable Type to WordPress for the first time, so not up to speed yet on all WP procedures.

  19. Hans

    Hi, I´m trying to get the multisite in 3.0 to function but it wont. In fact it was working earlier for me with beta 1.
    Now after installing RC I just dont seem to get it right. Been trying several installations, but no!

    Problem is that everything works fine including “add a new site”. But when I’m trying to reach that site either from backend or on front, it just goes ” error 404 – Object not found!

    Please what am I doing wrong here.

  20. Hans

    Ok, this is resolved now.
    What we did was two things in httpd.conf (not sure wich one actually solved it)

    1. Changed

    Options FollowSymlinks
    AllowOverride Fileinfo Options
    Order deny,allow
    Deny from all


    Options FollowSymlinks
    AllowOverride All
    Order deny,allow
    Deny from all

    2 Changed
    # AllowOverride controls what directives may be placed in .htaccess files.
    # It can be “All”, “None”, or any combination of the keywords:
    # Options FileInfo AuthConfig Limit
    # AllowOverride None to
    AllowOverride All

    Thanks Andrea for getting us on the right track!

  21. This is a really exciting development!

    However I was wondering about different URLs…
    For example – my main URL is, and I create a new wordpress site for a client – In wordpress 3.0, am I correct in thinking the URL has to be in the format of or
    If this is the case, how could it be used to create a site with its own base URL, like ?

  22. WordPress 3.0 works perfectly, but I am still missing the way to save different sets of plugins and only having to turn on or off the set, I am missing the ability to quick select the categories, just start typing the name of the category and this is filter for easier selection, I am missing a better image resizing or editing, anyway, I love wordpress.

Leave a Reply