Should You Install a Forum on a Subdomain or Root Site?

There are three options for installing a forum on your site. We’ve already written about reasons why you might want to create a forum for your site, so I won’t cover them here again. Instead, let’s just assume that you’ve decided it’s a good idea, and you’re trying to figure out what kind of implementation you want.

The three options are to install it: at the root, install it in a root subfolder, or install it on a subdomain. What do each of these three options mean? If you were to navigate to the front page of your forum, this is how you would do it:

1. Root: www.example.com brings you to the forum.
2. Subfolder: www.example.com/forum/ brings you to the forum.
3. Subdomain: www.forum.example.com brings you to the forum.

There are advantages and disadvantages of each method.

The Root Method

I’m going to be brief here with the root method, because I’m assuming it’s not going to work for you. If you’re deciding to implement a forum, it means you have a website that has a good deal of traffic and power to it. That means you have an established site on an established domain. Going to www.example.com probably brings users to your homepage, right?

If you were to change this front page to a forum, you suddenly run into issues. Where do people go when they want to reach your homepage? Do you have to implement redirects? You’re probably going to lose a lot of SEO power to your homepage, and while that might not be the central focus of your traffic, you’ll also lose value across your site. On top of that, you’ll end up confusing existing readers who expect your homepage and are now getting a forum they may not care about.

The only time you would want to install a forum on the root directory is when you’re starting a site up fresh and you want the forum to be the main focus. If you’re setting out to build a community, rather than establish a community centered around your existing traffic, you can install it on root. Otherwise, make it one of the other options.

The Subdomain Method

Next I’ll go ahead and cover the subdomain option. In this option, you get to pick a subdomain of your choice and make it your forum home URL. You could do something like forum.example.com, support.example.com, community.example.com, or whatever else seems to fit the purpose of your forum the most.

Now, this isn’t exactly uncommon, but I would say it is getting a little less common over the last few years. There’s a lot of information floating around about whether a subdomain or a subfolder is best for divisions in your site, for various purposes, and some of the information is either old or is based on suppositions that no longer hold true. Let’s address each point.

First of all, the subdomain method looks a little sketchy and can look like a free site. A lot of people in the past used free web hosts that tended to host spammy content and lace it with ads. Other, more high profile and legitimate sites would and still do use that method, including WordPress.com. Any time you see a non-custom-domain free WordPress site, it tends to look like example.wordpress.com. Thus, the first possible gripe is that your forum might look from the outside to be a freesite expansion, which isn’t very good.

However, as the current crop of young web users mature, this implication is slowly going away. More people are used to seeing the subdomain as a division of a site ownership, like with WordPress or Blogger, or even with About.com, than they are to associate it with a freesite.

However, that leads to another issue; the division of ownership. Google and other search engines are used to treating subdomains as divisions between major sections on a site, such as with different owners for different WordPress blogs. They don’t want to make each individual section share PageRank and link value with each other, or it would make a site like WordPress an instant must-have for SEO. Just imagine being able to create a brand new site and get hundreds of thousands of related links immediately. It would be abused to no end.

Now, the official word is that there’s not actually an SEO division between subdomains and subfolders, but that’s coming from a lot of old Matt Cutts statements, one of which I’ll talk more about down below. That’s not always the most reliable or more clear source of information, and it’s obvious that Google does have a subdomain separation in some cases.

In large part it depends on the clarity of purpose and unification of branding between the root domain and the subdomain. If the two pages are significantly different, they will not share much of their SEO value. If they are very similar, they will share more. Unfortunately, the home page of a forum and the home page of a site tend to look and feel very different. There’s only so much you can do with branding, and you will have to do all of it in order to ensure that your pages share their search value.

Of course, that only matters if you want your forum to be publicly indexed and to be a source of ranking. If you don’t care, like if it’s a private forum or if it’s there more for support than for ranking value, you don’t have to worry at all. It won’t drag your site down unless it fills up with spam, it just won’t benefit you as much as a more clear link like a subfolder.

There is a more technical reason to shy away from subdomains, and that’s the technical knowledge necessary for running it. Various technical issues can crop up, including issues with managing and reading cookies across both the subdomain and the root domain. SSL security is another big one, which is becoming more and more of an issue in modern days. If you want to use one SSL certificate for your root and sub domains, you will need to buy a wildcard certificate. They tend to be more expensive than comparable non-wildcard domains, because they need to verify different variations on URLs instead of just one base URL.

This is only an issue if you have a very tight budget or very limited access to technical support, however. If you don’t care about SSL or you don’t track using cookies, it’s a more minimal reason to shy away from subdomains. Still, it’s all-around easier to use a subfolder, so that’s what I would probably recommend, particularly if you’re big into detailed tracking and management of security.

Finally, there’s the conceptual level. In the past, this hasn’t been an issue, because the web has been relatively limited. You might have a video.example.com subdomain for YouTube-like content, but that’s more rare these days. Now, subdomains are getting used for more complex divisions of a site. Rather than dividing the content of the site – like the shop, the blog, and the forum – they’re used for apps. You might have developers.example.com, apps.example.com, and so forth. Each subdomain is a different app, rather than a different sub-section of the primary site.

Now, this is just a question of organization. Many sites choose to use subfolders in the same way, and it’s largely a matter of preference. More on that in the final section, though.

The Subfolder Method

The subfolder method is arguably a heck of a lot easier, and that’s why it’s much more common for most applications on the web these days. With a subdomain, you have to go into your domain registrar or your web host and access the control panel to set up a subdomain. For a subfolder, however, all you need to do is log into your hosting and create a new folder in your web host. It’s identical to creating a new folder in your local computing environment.

With subfolders, you don’t have the issues you have with subdomains. Everything listed above – the security, the cookie tracking, the site separation, the freesite implications – are all non-issues with subfolders.

Because using subfolders is more common, it’s also what most forum applications support by default. For example, using PHPBB, if you wanted to set it up on a subfolder all you have to do is create that subfolder and let it rip. If you wanted to set it up on a subdomain, you would need to edit files and whatnot manually.

Subfolders have the opposite association as subdomains when it comes to conceptual purpose and organization these days. Where you’re more likely to see app1.example.com, you’re more likely to see sections of a site in subfolders. Example.com/forum, example.com/blog, example.com/store, these are all valid uses of subfolders.

Storefronts are perhaps the one variable here, as I see them more or less equally on both subdomains and subfolders. It really depends on whether the site considers their shop to be a subsection of their main site and thus puts it on a subfolder, or if they choose to put it in a subdomain because it’s more of an app and should be left to stand alone.

Now, I could be wrong about the whole conceptual separation between subdomains and subfolders, but I think I’m just a little ahead of the curve in specifying it. It’s a trend I’ve been seeing more and more of in recent years, and it’s probably going to expand and be more obvious just based on social pressure. I don’t think Google is ever going to mandate what types of content should be on a subdomain versus a subfolder, though, so you’re always free to do as you wish.

General Considerations

In addition to all of the above concerns, there are a few more general items you should keep in mind before you make your decision. They don’t fall under pros or cons of either system, so they’re set aside here, in a third section.

First, consistency is always going to be important. If you already have subsections of your site using either subfolders or subdomains, you should keep using the schema you’re currently using. If you have example.com/blog, you should not then go and create forum.example.com. This is just liable to confuse your users. They won’t know what to expect and they may be less likely to investigate sections of your site.

Of course, if you have a bunch of content on different subdomains and you’re finding it to be a lot of hassle, you might take the introduction of the forum as a good reason to tinker with the URL scheme and add subfolders for those sections as well. You’re going to run into issues with redirects and losing SEO value, but that’s going to be true no matter when you’re adding or redirecting content. It’s up to you to make the determination whether a migration is worth it or if keeping a disorganized legacy scheme in place is better.

Both methods are roughly equivalent as far as Google is concerned.

Matt Cutts mentioned this several times, including a video about the subject back in late 2012. He says “roughly” equivalent, however, and we know that in some cases – like the WordPress example – they can be very different. Again, though, it really comes down to the consistency of your branding. Your forum should have a name that matches your main branding, it should have your logo on it, and static copy should reference your primary content. You should also have a section dedicated to discussion of blog posts, which you can use to post links to your main blog in a visible way.

Finally, you always have one more option. The separate domain method is another choice. Rather than using either a subdomain or a subfolder, you can make an entire new domain with its own branding. If you have www.example.com, you can also make www.exampleforum.com. This gives you one major benefit, which is the ability to spin it off and make it into its own thing should circumstances call for it down the line. However, you lack the ability to start off connected to your main site, and you won’t have any SEO value until you build it through sheer force of community. It’s up to you whether this is at all viable.