Subdomain or sub folder? What is best for my SaaS marketing site?

Subdomain or sub folder: what is the better option for SEO? At some point when exploring options before you build your SaaS marketing site, you undoubtedly bump into this question. You’ve found a great product to build a blog, but it means you get a subdomain like blog.example.com. “No worries”, you think, “many big brands do this too. So it should be fine for my business blog too!”

Well, hold on. Unless you are a similar big brand (think: Apple, Nike, Disney, etc), the subdomain option can actually hurt your SaaS brand. In this article I want to explore the two option and provide the insights needed to be able to make the right choice.

What is the difference between sub folder and subdomain? #

Let’s get on the same page first. What is a sub folder? What is a subdomain? How are they different? Let’s grab a random link like the following:

1. Protocol
2. Subdomain
3. Domain
4. Top Level Domain (TLD)
5. sub folder
6. Slug

Maybe you don’t know it, but every link on the web consist of at least two of the above parts. A browser needs at least domain and a TLD. For example: spinalcms (domain).com(TLD). If you click on this link, you will notice your browser prepends it with the protocol (https). All the other parts are optional. This page you are looking at right now also has a sub folder (blog) and a slug (subdomain-or-subfolder).

So when we take two similar links:

1. example.com/blog/ and;
2. blog.example.com

For the first option: blog is a sub folder of example.com. For option two, _blog is a subdomain of example.com. And although Google treats the content roughly equal, the two are seen as two completely different sites.

That is where things get interesting: option one gives you more SEO for your buck, than option two does.

A sub folder helps with SEO authority of your domain. And at the same time help search engines understand your site front to back.

So the answer to “when to use sub folder or subdomain?” is: almost always. But when is a subdomain the better option and why do you still see them so often?

Subdomains and SEO don’t work well together.

When to choose a subdomain? #

If you visit many marketing websites, you might discover they host their blog, documentation and knowledge base on a subdomain. Why do they do that? We know it likely hurts their domain’s SEO authority. The reason is usually technical.

Many SaaS providers and publishing platforms, like Intercom, Ghost or Help Scout, allow you to publish content using their site. In order to provide the option to publish under their own domain, they provide a subdomain that can then be masked via DNS cname record.

Example for Ghost: example.ghost.io becomes blog.example.com. There are other options, using reverse proxies to be able to a have sub folder instead of a subdomain, but they require more moving parts and as a result quite more set up.

Another reason businesses deliberately choose a subdomain is when they provide a massive number of products and services. These products or services stand alone by themselves.

Other reasons are:

• you want to do a deep dive on a topic that you don’t want to add to your main site.
• you have a really specialised keyword; this could positively favour your SEO for that specific keyword.

There you have it. Have a smallish marketing site with similar topics: go for the sub folder route. Do you have multiple (standalone) products or services: go the subdomain route.

Written by July Forand

Published: 26 September 2022 (updated: 7 February 2023)