Even the average user can see that WordPress is a powerful and flexible platform. But there’s more to WordPress than meets the eye.
Just below the surface, and somewhat hidden away, there is an even more powerful mode that WordPress possesses – a mode called Multisite.
Enabling this mode allows you to turn a single WordPress installation into a network of sites. Thousands of sites, if you like. Hundreds of thousands. Even millions.
An Introduction to Multisite
While not for the average user and not something everyone will need, Multisite may be just what you’re looking for if you have a situation that requires a more robust approach than a single WordPress install allows for.
Our hope here is to give you an overview of what Multisite is and to help you decide if it might be right for you.
We’ll cover the following:
- Why Run a Multisite Network
- Is Multisite for You?
- Examples of Multisites in the Wild
- When Not to Use Multisite
- Advantages and Disadvantages
- WPMU DEV Multisite Plugins
- Differences from Regular WordPress
- How to Activate Multisite
What Exactly Is Multisite?
Multisite is a feature (or a mode) within WordPress that allows you to run a number of different sites from one WordPress installation.
All the sites in the “network,” as it’s known, will share all the same plugins and all the same themes.
(Note – with special plugins like Pro Sites from WPMU DEV, you can control access to plugins and themes – for example, allowing User A access to all plugins and themes but allowing User B access to only a few of the installed plugins and themes. You can also do this in a more limited way with the out of the box version of Multisite.)
All the sites also share one database; however, they do have separate tables within the database, and they also each have their own directories for media uploads.
Why Run a Multisite Network
There are different reasons why you may choose to run Multisite. Below are a few of the most common.
1. Host Sites Open to the Public
One of the most common reasons for running a Multisite Network is to allow users to sign up for their own blogs/sites, as sites such as wordpress.com and edublogs.org do.
Multisite can be set up to allow users to create a new site automatically with no extra work needed from the administrator. Typically new blogs will reside at a URL that looks like one of the following:
The difference here is the difference between setting up sites as subdomains or subdirectories. (More on this later.)
Using Multisite in this way could work in many niches — for example, giving users their own sites so they can blog about gardening, surfing, dieting, traveling, music, education, etc., etc. The list really is nearly limitless.
2. Host an In-House Network of Sites
Another common reason for using Multisite is when one person or one organization would like to run a number of different sites from one installation, thereby making it easier to update plugins, themes, and WordPress itself. When all your sites are on one installation, it also makes it easier to access the Admin areas of different sites from one main control panel.
Here are a few examples of when this type of Multisite network might be ideal:
- Different schools in a school district
- Different departments in a company/university/newspaper/etc.
- Different teams in a league
- Different stores/branches in a chain
- Different cities in a state/country … Different countries in the world
- Different events in a location (e.g. festivals, concerts, etc.)
- Different shows on a radio station
Is Multisite for You?
With all those “differents” above, however, you should ask yourself an important question: Do I really want these sections/sites to be different?
In other words, can I just use “categories” on a regular WordPress install and achieve the same thing?
If you can say YES to any of the following below, then you Multisite may be the way for you to go:
- Do I need a different themes on the same site?
- Do I need different plugins/functionality for different sections?
- Do I need to give access to different administrators/editors for the different sections?
- Do I need different top level addresses (e.g. mapping colors.com/red/ so that resolves to red.com)?
Examples of Multisites in the Wild
Below are a few Multisite we’ve found out in the wild. You can browse some more for yourself at the WordPress.org Multisite Showcase section.
WordPress.com – Open to the public. It is the largest Multisite-based site on the web.
Edublogs.org– Open to the public, but limited to educational purposes. This site, run by the same company that runs wpmu.org and wpmudev.org, is the second largest Multisite example on the web.
Harvard Law School Blogs – Open only to students associated with Harvard.
Reuters Blogs – Contains a different site for each writer. While it looks like each writer simply has a different “section” from the frontend, in the backend they would actually have their own blogs. In this way, one writer cannot access another writer’s Admin area.
Tradr — A site that provides commercial platforms with integrated marketing tools.
BBC America – Presumably, each show is a different sub-site. While this can be done with categories, it probably makes more internal sense for the BBC to silo off each show into its own backend. This way those with permissions on one site don’t necessarily have permission on another site.
Teatra – A “social marketplace“ for people to buy and sell tea.
Yacht Blogs – Open to the public. For all those interested in yachts.
Mission’s Place – Run by our own Aaron Edwards, this site is open to missionaries.
When Not to Use Multisite
If you don’t need to use Multisite, then it’s probably better not to activate it. While it might not make much of a difference one way or another, there is a chance that you might run into some issues that you don’t really need to deal with.
Don’t use Multisite if …
- categories will do
- you need different user databases (for special security reasons, for example)
- users need to install their own themes or plugins
Some argue that you shouldn’t use multisite if you’re running small client sites. When asked why, most will end up saying that it’s just “cleaner.” And by that they mean that because you have totally separate databases with single installations, it’s easier to transfer the site somewhere else if needed.
That said, you CAN “peel off” a site from a Multisite network by using the Import/Export functions native to WordPress. If you would like to take a site from your Multisite network and turn it into a single installation, then do the following:
- Set up a new install as you normally would
- Export the networked site’s content with the Export function
- Import the site’s content to the new single installation
You can find a detailed explanation of importing/exporting with Multisite here.
WordPress also has a page on migrating several Multisite blogs.
(On a somewhat related note — you can import/export single categories in WordPress.)
Advantages and Disadvantages
OK, so we’ve somewhat hit on the advantages and disadvantages of using Multisite in different ways already, but let’s go ahead and list some out here in a more direct way and maybe touch on a few we haven’t gotten to yet.
- Automatic site/blog creation for any user
- Automatic blog creation for a limited set of users – e.g. restrict by email or with a special code (need a plugin for the special code – see below)
- Unlimited site-creation for one user
- Limited site-creation for one user (with a plugin – see below)
- Limit the amount of uploads (or make it unlimited)
- Different themes on different parts of your site
- Changes to a theme will apply to that theme on all the sites that use it
- Users still have the ability to place things such as widgets, menus, headers, and backgrounds onto their sites, regardless of their theme (to restrict this, see plugins below)
- Users can create and manage multiple sites (or restrict them to one with a plugin – see below)
- Sites can be completely separate from each other, or they can be integrated in a number of ways
- Activate themes on a site-by-site basis
- While not “difficult,” it does require the admin to learn how to manage the network, which is a little more involved than a regular WordPress install
- You need access to your server – must be able to edit core WordPress files
- Some themes don’t always work so well with Multisite (most do, but I’ve run into some that don’t)
- Some plugins might not always work so well (again, as above, most do)
- If you have problems with the core installation, or the main site gets hacked, then all sites in your network may be affected
- While it’s possible to tie sites together, it is a little more difficult to display content from various sites onto the main homepage, for example. But it’s not impossible. WPMU DEV plugins will help you do that.
WPMU DEV Multisite Plugins
As with regular WordPress, a lot of the limitations you find with an out-of-box install can be overcome with plugins.
As most everyone who’s bothered to look into it knows, WPMU DEV is THE site on the web for Multisite plugins. There are literally too many to go over here. But will give you a quick rundown of a few things you can do with DEV Multisite plugins.
Pro Sites — Offer upgrades and charge users, like WordPress.com or Edublogs.org, offering your users premium themes, premium plugins, extra storage, advertising, domain mapping and more.
Anti-Splog – Stop spam blogs (splogs) from registering on your network and taking the whole thing down the toilet.
New Blog Templates – Create a template blog (or many!) and then duplicate every single setting (content, theme, categories etc.) for every new blog.
Domain Mapping – Let users use their own domain names for their sites. For example, turn site1.mysite.com into simply site1.com.
Multisite Analytics – Offer users individual stats for their sites through Google Analytics. At the same time, get site-wide stats for yourself.
Site Categories – Create site categories for your whole network.
Ad Sharing - Split ad revenue with your users.
Recent Global Posts Feed – Get a feed of all the recent posts across your entire network.
Blog Activity — Collect info on how many blogs across your network have been updated.
And many, many more. See the full list here.
Differences from Regular WordPress
One of the main differences you’ll come across is the role of Super Admin. As the Super Admin, you control the whole network. That means you decide things such as which plugins are available, which themes are available, whether just anyone from the web can sign up and get a site, or whether you’re going to restrict your network.
The Super Admin will have access to a backend for the entire network, a backend for the main blog on the site, as well as the backend of any other blog created for the site.
Navigating between these different backends may get a little confusing at times, and it may be a little difficult to figure out where you need to go in order to control something that you want to control, but other than some slight frustration, this is not really such a problem for someone determined to run Multisite.
(Check out how to create multiple levels of Super Admins here.)
Set Up Choices
Of course you will also have different choices to make when you set your site up. For example, will you allow public registration? If so, you’ll likely need to look into plugins like Anti-Splog, which will help you control spam blogs (splogs).
You will need to think deeply about what you want to give your users access to. Some things may be easy to cut off. Others will require finding the right plugin.
Finding the right plugins, whether they’re security plugins or plugins that help you display content more flexibly, will allow you to truly make your Multisite install work the way you envision.
Managing Plugins and Themes
As mentioned, you will have need to control which plugins and themes are available to your users. Maybe you would like everyone to use the same theme. Maybe you’d like to give users a choice. It’s up to you.
You can also manage theme choice on a site-by-site basis, giving certain sites more choices, or picking and choosing one theme for one site and another theme for another site.
While none of the above is particularly difficult once you get the hang of it, it should be noted that being a Super Admin for a Multisite install is different from being an Admin for a regular WordPress install. And there is a learning curve. If you struggle with a single WordPress install, then you may want to become more comfortable with the basics before moving onto Multisite.
BuddyPress is essentially a giant plugin that lets you create a fully-formed social network for users of your site.
While you don’t need to run Multisite to use BuddyPress, and you don’t need to run BuddyPress if you’re running Multisites, many sites using Multisite do use BuddyPress.
Of course it all depends on what you want your Multisite to do for you. If you’re looking to tie all the different users in your network together, then BuddyPress is a good option for you.
For some Multisite installations, however, tying everyone together is the exact opposite of what you want.
All that said, BuddyPress is really a whole ‘nother ball of wax. But we thought we’d at least mention it here as something worth considering if you’re thinking about starting a Multisite Network. (See our BuddyPress section.)
Below are a few resources that you will absolutely want to consult if you plan on running a Multisite Network.
- See all of WPMU DEV’s Multisite plugins
- Check out our Multisite Manual
- Join our community for Multisite info
- See the WordPress.org forum for Multisite questions
How to Activate Multisite
And finally, we’ll get into actually activating Multisite.
Although Multisite is a feature of all WordPress installations, you will still need to activate it before it is visible. As mentioned in the very beginning, it is hidden away from the casual user.
Before moving onto any instructions, you should know that you are most likely going to need to choose between setting up new sites as subfolders or subdomains. And so let’s go over that quickly.
Subfolders and Subdomains
Little works as well as an example, so let’s start with a few examples.
Subfolders look like this:
Subdomains look like this:
Depending on exactly how you’re setting things up, some of you may not have a choice. For example, if you try to activate Multisite on a site that is ALREADY in a subfolder, you will only have the choice of setting up more subfolders.
For example, let’s say your site titled “mysite” is located here:
You’re new sites will then be added on as additional subfolders:
Some people may run into problems with their server when trying to set up sites as subdomains (e.g. site1.mysite.com). If you have an upgraded hosting account (such as a virtual private server account, for example), you may be able to call your webhost and get them to help you out with it. If not, you’ll just have to go with subfolders.
Which is Better?
This is a personal preference. If you’re trying to set up a public blogging site like wordpress.com, for example, some believe that it’s more attractive to users to have the name of their site first – e.g. site1.mysite.com.
At least in the old days of SEO (I’m not sure anymore), it was said that having subfolders (e.g. mysite.com/site1/) was slightly more attractive to the search engines.
Once you choose, there’s really no turning back, however. So just pick one and don’t worry about it anymore.
With a domain mapping plugin, you can make it seem as if your Site1 site or your Site2 site is just a single install of WordPress.
For example, mysite.com/site1/ or site1.mysite.com can be made to resolve to the domain site1.com. No one will ever know the difference.
Even users in the admin area will not know they are on a multisite network if you don’t want them to. Their admin dashboard will appear at site1.com/wp-admin/ just like any regular WordPress site.
Turning on Multisite
Activating Multisite is not difficult, but it requires more than simply clicking a button or two. You should know that you will need access to the core WordPress files on your server.
We have also made you a video of the process.