Ever heard of WordPress Multisite? We just came across a project that Multisite is great for, so I thought I’d take a bit of time and do a quick writeup.

So what is multisite?

In a nutshell, Multisite creates a network of websites from a single WordPress install. You can manage each site individually, or all at once, depending on your access privileges.

A few key points:

Single WordPress Install. There is a single WordPress install on the server that runs all the different sites.

User Roles. For typical users, each site is the same as a normal WordPress site, with the usual roles (Admin, Editor, Contributor, Subscriber). Multisite adds a “Super Administrator” role, and that person can administer any or all the sites in the network.

Network Dashboard. A new Network Admin dashboard allows Super Administrators access and control over all network sites from a single dashboard.

MultisiteNetworkAdmin

Compartmentalize Users. Each site on the network will have their own admin dashboard, and users can be assigned to individual sites with the usual roles like Administrator, Editor, etc. For instance, I set up a Site B user with Editor privileges. This person can access the admin area at <code>siteb.example.com/wp-admin</code>. They have Editor privileges for Site B only, and cannot see admin pages from, or make edits on, Site A or Site C.

Subdomain or Subfolder. You can decide whether each site on your network will be located on a subdomain (e.g. sitea.example.com, siteb.example.com) or a path (example.com/sitea, example.com/siteb). The main domain, example.com, also houses a site, and this can be useful for directing visitors to the other sites in your network.

Plugins. Plugins are installed and activated at the Network Admin level only, and cannot be installed or uninstalled on the individual network sites. If I install and activate an SEO plugin, say, then it is active on all sites with the same settings. Depending on the plugin, individual site users may be able to deactivate or change options on a site-by-site basis. Beware! Many plugins will have problems if used on a Multisite network. Be sure to test them thoroughly before production use!

Themes. Similarly, themes are installed only at the Network Admin level, but can be activated and deactivated at the site level. This way each of your network sites can use a different theme (or the same one if you want).

Content. Actual content is changed at the individual site level, so each site’s content will be unique, but the format is determined by a global or individual theme (see Themes above) that the Network Admin has set.

For the most part, Multisite can essentially be business as usual, just with more compartmentalized access for most people, and one person wielding all the power.

What Multisite is great for

A business with multiple locations, where each location needs its own unique, compartmentalized content.

An educational institution with different departments or locations, that similarly need their own navigation and content.

Theme development. Set up and testing custom themes in a development environment (or a live one, I suppose), without having to deal with a bunch of installs and databases.

Company blog network. Running a network of company blogs, all separate but related. Only if you want these to exist as their own separate websites.

What it’s not so great for

While Multisite is great, it was built with a particular purpose in mind. Some applications that are not so great:

Managing your clients’ websites. While it may sound attractive to house multiple sites under one roof, different sites with varying purposes, functionality and user groups on the same install can be problematic. Heptagon’s rule of thumb: If there isn’t a central hub that ties all the sites together, don’t use multisite.

Your blog. Typically your blog is better structured as a single site, even if you have multiple authors or topics. That’s what WordPress (single install) is made for.

Setup

We may write a detailed Multisite setup article down the road, but for now I’ll just point you in the right direction:

Start by reading the documentation in the WordPress Codex http://codex.wordpress.org/Create_A_Network

Once you’re sure Multisite is what you actually need, check with your web host. There are some different server requirements than a regular ol’ single WordPress install, so make sure your server can handle it. Some shared hosts won’t touch Multisite (or if they do, performance won’t be great).

Follow the Codex instructions. It’s pretty similar to a typical WordPress install. There are some automated tools out there [http://codex.wordpress.org/User:Beltranrubo/BitNami_Multisite], but we always recommend manual setup to gain a better understanding of how the site works.

Good luck! As always, if you have anything to add, let us know below.