Websites · Glossary
What is a subdomain?
A subdomain is an extra name placed in front of a registered domain to create a separate address, such as shop in shop.example.com or blog in blog.example.com. The owner of the domain can create as many subdomains as they like through DNS records, and each can point to a different website or service.
Every web address you type has a structure read from right to left: the top level domain, the registered domain, and any subdomains in front of it. Website builders use subdomains to give each new site a free address.
Nuwan Madhusanka · Co-founder
3 min read · Published
How a subdomain is built
Take shop.kilnandtide.com.au. Reading right to left, au is the country code, com.au is the second level, kilnandtide.com.au is the registered domain the owner pays for, and shop is a subdomain. The owner creates it by adding a DNS record, usually a CNAME or an A record, that tells browsers where that name lives.
Why platforms give you one
A builder owns its own domain, so it can create a subdomain for each customer site at no cost: yourname.platform.com. It works immediately, with no registration or DNS changes, which is why it is the default address when you first publish.
Uses for your own subdomains
Businesses with their own domain use subdomains to separate jobs: shop for a store hosted on another platform, book for a booking system, launch for a campaign page, app for a web application. Each can be hosted in a different place while staying under one brand.
Common mistakes
Treating www as optional without setting both versions up, so one of them fails. Creating subdomains for every small page instead of using paths such as /services. And forgetting that a subdomain on someone else's domain, such as a free builder address, belongs to that platform, not to you.
Where it shows up in OneCraft
Every site gets a free subdomain on onecraft.live, made from the site title, such as saltbush-physio.onecraft.live. You can rename it in site settings using 3 to 40 lower case letters, numbers and hyphens; a live site keeps its old address as a redirect for 30 days. On a paid plan you can connect a subdomain of your own domain instead.
Questions people ask
Is www a subdomain?
Technically yes: www.example.com is a subdomain of example.com. By convention it is the main website, and most sites make www and the bare domain lead to the same place, one redirecting to the other, so visitors reach the site whichever they type.
Does a subdomain cost money?
Creating subdomains of a domain you own costs nothing beyond the domain itself; you add DNS records for each. A subdomain on a platform domain, like a free builder address, is also free, but it stays under the platform name rather than yours.
Is a subdomain bad for SEO?
No. Search engines treat a subdomain as its own site in many respects, which is fine for a separate store or app. For content that belongs with your main site, such as a blog, a path on the main domain keeps everything in one place and is usually simpler.
Can I move from a free subdomain to my own domain?
Yes. Add your domain in the site settings, set the DNS records your provider needs, and once it is live make it primary. The free address then redirects to your domain, so links you shared before keep working and search engines follow the move to the new address.
How many subdomains can a domain have?
DNS sets practical limits far beyond what any small business needs. Each subdomain is just another name with its own record, so you can create one for each tool you use without buying anything new. Keep a short list of which subdomain points where, so old records do not linger after you stop using a tool.
Make one with websites
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Create a website with OneCraftRelated questions
- Custom domain vs subdomainCustom domain vs subdomain: a domain you own like yourbusiness.com versus a free platform address. Cost, trust, portability and search compared in a table.
- What is a CNAME record?What is a CNAME record? A DNS entry that points one name, like www.yourdomain.com, at another name. What it does, why builders ask for one, and the apex catch.
- What is an A record?What is an A record? The DNS entry that points a domain name at an IPv4 address. How it differs from a CNAME and when a website builder needs one.
Written and checked by the OneCraft team. Last checked .