Subdomains and subfolders

What are subdomains and subfolders?

Subdomains and subfolders are two ways to structure a website when you want to create a clear overview of your content. A subdomain works as an independent section that sits in front of the main domain and is separated from it by a dot. You typically use it for a separate function, such as a blog, a webshop or a support hub. In principle, a subdomain can work as a standalone website, because it can be hosted separately and have its own technical settings.

A subfolder, on the other hand, is part of the main domain's structure. It is placed after the domain name and separated by a slash. In practice, it's simply a folder in the domain's file structure, and it inherits the domain's authority, technical setup and Analytics data. Subfolders are most often used when the content is closely tied to the main site – for example domain.com/knowledge/ or domain.com/blog/.

In other words: subdomains create separate sections, while subfolders keep content together under the same main domain. The choice affects the technical structure, SEO and the way users navigate.

How do you use subdomains and subfolders?

You can use subdomains when you need to isolate parts of your website technically or organisationally. You might want to run a webshop with its own backend or an improved design without changing the whole main site. Because subdomains can sit on separate servers, you can give different teams responsibility for each section – for example marketing on the main site and development on a technical subdomain.

Subfolders, on the other hand, give you a unified structure. They're ideal when you want your whole website to come across as a single, cohesive whole – both to users and to search engines. In a CMS such as WordPress, you typically create subfolders automatically when you make new pages or categories. This means you can quickly build a deep information architecture without touching the server settings.

In practice, both SEO and user experience play a part in what you choose. Subdomains often require separate tracking and optimisation in Google Analytics and Search Console, while subfolders automatically share the same account. If you work on SEO strategy at an agency, it's therefore worth considering how the split affects the distribution of authority and the link structure.

Why use subdomains and subfolders?

When you organise a website, it's not just about clarity. Your structure affects both your visibility in search engines and your technical performance. Subfolders are often preferable for SEO, because search engines see them as part of the main domain and therefore give them the same authority. This means new pages can rank faster, because the main domain has already built up trust and links.

Subdomains do have their advantages, though. They give you flexibility, so you can test new designs, features or campaigns without risking a negative impact on the main site. In a broad digital strategy, you can for example use subdomains to target different geographical markets with local language versions. This makes the setup easier than launching entirely new domains and gives you better control of traffic and communication.

Whatever you choose, a deliberate structure creates a better foundation for both SEO and paid advertising. When you work with Google Ads, for example, you can use subfolders to segment landing pages by campaign type, so you can measure performance more precisely. At the same time, a clear hierarchical structure helps social media and external links point to the right place on the site.

What types and variants are there?

You can think of subdomains as separate units with their own addresses. Typical examples are:

Each of them can work independently while still being linked to your brand. “www” is actually also a classic subdomain, although most people no longer see it as a separate area.

Subfolders are often used for categories, campaigns or information structures. They can look like this:

They can be created manually or through your CMS. The big difference is that subfolders always keep their connection to the main domain, both technically and for SEO.

How do you use subdomains and subfolders in practice?

In practice, it's about choosing the solution that works best with your overall strategy. If you're planning a global site in different languages, subdomains such as en.domain.com and fr.domain.com can make sense, because you can host them close to local users and optimise them technically for each market. But if your focus is on concentrating all your authority in one website, you should choose language structures with subfolders instead, for example domain.com/de/ and domain.com/fr/.

You create subdomains through your web host's DNS settings or control panel. This is where you define which server or folder the subdomain should point to. Subfolders simply require you to create a new folder on the server or a subpage in the CMS. Most hosting providers offer tools that let you do both at no cost and with relative ease.

When you want to measure the effect, you can integrate each section in Google Analytics or similar tools, but be aware that subdomains don't automatically share data. That's why you should configure tracking and internal links carefully – especially if you work with SEO and performance marketing across websites. That way, you can see the whole customer journey without gaps in the data.

What should you be aware of?

Before you decide to use subdomains or subfolders, you should be clear about your technical resources and your purpose. Subdomains often require more setup, because each area needs its own configuration, SSL certificate and tracking. That gives you flexibility, but also more things that can go wrong. Subfolders are simpler, but they require you to think through navigation and structure from the start, so the pages don't get lost in too many layers.

You should also consider how your choice of structure affects your link building strategy. Links to subdomains aren't automatically passed on to the main domain, while links to subfolders strengthen the site as a whole. If you work with content marketing, it can therefore be an advantage to place your blog and knowledge content in subfolders rather than on separate subdomains.

Finally, you should look to the future: does your site need to be scalable, easy to expand and SEO-friendly? If so, a well-organised folder structure typically delivers the most value in the long run. But if you often run separate campaigns, landing pages or microsites with unique designs and tracking, subdomains may be the most flexible solution.