What Is a Subdomain? A Simple Guide for Beginners (2026)

A subdomain is the extra word that sits in front of your domain name. Take blog.example.com. Here, “example.com” is the main domain, and “blog” is the subdomain. It lets you create a separate section of your website that still belongs to your main domain.

Last updated: November 2026

You have probably used subdomains many times without thinking about it. When you visit help.example.com for support, shop.example.com to buy something, or app.example.com to log in to a tool, you are on a subdomain.

This guide explains what a subdomain is, how it is different from a subdirectory, when you should use one, and how to set one up. If you are still new to the basics, it helps to know what a domain name is first, and the difference between a domain and hosting.

What is a subdomain?

A subdomain is a prefix added to the left of your root domain — the part you own, such as example.com.

• blog.example.com — “blog” is the subdomain.
• shop.example.com — “shop” is the subdomain.
• help.example.com — “help” is the subdomain.
• app.example.com — “app” is the subdomain.

Each subdomain can point to different content. Your main site might be a company homepage at example.com, while blog.example.com shows your blog, shop.example.com runs your store, and help.example.com holds your support articles.

A subdomain can run on its own server, platform and settings, with its own hosting if needed. That is one of the main reasons people use them. Your main site might be a simple WordPress site, while your store runs on a separate e-commerce platform and your help centre runs on a hosted support tool.

Subdomain vs subdirectory: what’s the difference?

A subdirectory is also called a subfolder. It sits to the right of your domain, after a slash. Compare the two:

• Subdomain: blog.example.com — the word goes on the left, before the domain.
• Subdirectory: example.com/blog — the word goes on the right, after a slash.

Both lead to a section of your site, but they are built differently. A subdirectory is part of your main site’s structure and routing. It shares your main site’s platform, design and settings. A subdomain is a separate branch — it can have its own platform, design and even its own server.

How does Google treat subdomains?

This is the question most site owners ask, and Google has answered it more than once.

Matt Cutts, who was then head of webspam at Google, said in 2012 that subdomains and subdirectories are “roughly equivalent” for search. John Mueller of Google said in 2017: “Google websearch is fine with using either subdomains or subdirectories” and “In general, we see these the same.”

So there is no big ranking bonus for picking one over the other. What matters more is how the subdomain connects to your main site. A subdomain that is internally linked from the main site and shares navigation and design is usually treated as part of the same site. One that lives in isolation, with no internal links and a different look, can be treated as separate.

There are a couple of other things worth knowing:

• A Google Search Console Domain property covers every subdomain of your domain. A URL-prefix property covers one exact address, so you would need one for each subdomain you want to track.
• Moving content between a subdomain and a subdirectory can cause temporary ranking swings, so only move with a real reason. A redesign or a platform change is a real reason. Chasing a small SEO gain is not.

When should you use a subdomain?

For most content — your blog, your guides, your resource pages — a subdirectory is the better pick. It builds on your main domain’s strength, it is simpler to manage, and everything stays in one place.

1. A logged-in web app or dashboard

If your product is a tool people log in to, it usually lives on app.example.com. The app is built with different technology from your marketing site, and it needs its own login system. A subdomain keeps it apart cleanly.

2. A help centre or docs site on a hosted platform

Many support tools only publish on a subdomain. If your help centre runs on a hosted platform, it will live at help.example.com or support.example.com.

3. A store on a separate platform

If your main site is a simple company site but your store runs on a separate e-commerce platform, shop.example.com or store.example.com is the usual answer. The store needs its own checkout and payment setup, so it works best on its own.

4. Different languages or regional sites

Regional versions of a site often use subdomains: uk.example.com for the UK or de.example.com for Germany. Each version can have its own content and currency while staying under one brand.

5. A clearly separate product or audience

Sometimes one company runs two very different products. Giving each one its own subdomain keeps them apart while keeping the brand link.

When should you use a subdirectory instead?

Use a subdirectory when the content belongs with your main site and you want it to add to your main domain’s strength. That covers your blog and news posts, guides and tutorials, resource pages, and product or service pages.

If the content is written for the same audience as your main site and links naturally to your other pages, a subdirectory is the simpler and stronger choice.

There is one more reason to think about this early. Moving a blog from blog.example.com to example.com/blog later — or the other way round — means redirects, a wait while search engines adjust, and often a short dip in traffic.

How to create a subdomain

Creating a subdomain is a short job. You do it in one of two places: your hosting control panel or your domain registrar. Which one you use depends on where your site is hosted and how your domain is set up.

Option 1: In your hosting control panel

Most shared hosting uses cPanel or a similar panel. In cPanel, go to Domains and then Subdomains. Type the subdomain name you want — for example, “blog” — and pick the folder it should point to. The panel creates the subdomain and the folder for you.

Option 2: At your domain registrar

If your domain’s DNS is managed at your registrar, you add a DNS record there instead. Two record types are common:

• A record: points the subdomain to a server’s IP address. Use this when you know the IP of the server that will host the subdomain.
• CNAME record: points the subdomain to another hostname. Use this when a hosted platform tells you to point your subdomain at an address they give you, such as a support tool or a store platform.

Your registrar or hosting provider will tell you which record to add and what value to use. Follow their steps exactly — a wrong record is the most common reason a new subdomain does not load.

Changes can take minutes to a few hours to work everywhere (DNS propagation). A wildcard SSL certificate covers all subdomains of a domain, so visitors see the padlock on blog.example.com, shop.example.com and any other subdomain you add.

Subdomain examples in real life

Here are some patterns you will see every day. Notice that the subdomain name tells visitors what they will find. “Blog”, “shop”, “help” and “app” are all plain words. That is the best naming rule: keep it short, clear and obvious.

• blog.example.com — a company blog kept apart from the main site.
• shop.example.com — a store on a separate platform.
• help.example.com — a support centre on a hosted help tool.
• app.example.com — the login area for a web app.
• uk.example.com — a regional version for UK visitors.
• mail.example.com — often used for email servers, not a website at all.

Common mistakes to avoid

• Putting your blog on a subdomain for no reason. If your blog is written for the same audience as your main site, a subdirectory is usually better.
• Launching a subdomain and never linking to it. Link it from your main navigation and link back.
• Using a different design with no shared navigation. If the subdomain looks like a different company, visitors will treat it like one.
• Forgetting the SSL certificate. A subdomain without a working certificate shows a security warning. Check it loads over HTTPS before you share the link.
• Moving content without a plan. Set up redirects first, and only move when there is a real reason.

Frequently asked questions

Is a subdomain a separate website?

Not quite. A subdomain is a separate section under your main domain. It can run on its own server and platform, but it still belongs to your domain. How separate Google treats it depends on how well it is linked to your main site.

Do subdomains hurt SEO?

No. Google has said subdomains and subdirectories are roughly the same for search. What matters is the quality of the content and how well the subdomain is linked from your main site.

What is the difference between a subdomain and an addon domain?

A subdomain is part of your existing domain, like blog.example.com. An addon domain is a completely different domain, like exampleblog.com, hosted on the same hosting account.

Can I have more than one subdomain?

Yes. You can create as many as you need — blog, shop, help, app and more — as long as your hosting plan allows it. Most plans allow plenty.

Does a subdomain need its own hosting?

Not always. A subdomain can share your main hosting account and point to a folder on it. But it can also run on its own server or platform if needed — for example, when your store or app uses different technology from your main site.

Why is my website not showing on Google after I created a subdomain?

A new subdomain takes time to be found and indexed, just like a new page. Make sure it is linked from your main site, check that it loads over HTTPS, and add it to Google Search Console. If other pages have the same problem, read our guide on why your website is not showing on Google. Getting the basics right across your whole site helps too — including small details like what a favicon is.