Use a subdirectory (yourdomain.com/blog) when the content is part of the same site and you want it to inherit your domain's SEO authority. Use a subdomain (blog.yourdomain.com) when the content genuinely needs to run as a separate site: different software, different server, or a deliberate technical or organizational split. If you're unsure, default to a subdirectory. It's simpler to set up and easier to manage long-term.
The confusion usually comes from the fact that both look similar in a URL bar but work completely differently under the hood. A subdirectory is just a folder path on the same install. A subdomain is treated as a distinct hostname with its own DNS record, and often its own document root.
How each one actually works
A subdirectory lives entirely inside your existing site's file structure. If your site is a WordPress install at your account's document root, /blog is just a folder (or a WordPress permalink rule) inside that same install. No DNS changes, no new hosting setup, nothing to point anywhere. It shares your domain's SSL certificate, your existing PHP version, and your existing database unless you deliberately connect a new one.
A subdomain needs its own DNS record before anything can be served on it. That's an A record or CNAME for blog pointing at your server, added in your domain's DNS records, alongside your existing root and www records. Once that record resolves, you decide what serves it: a folder on the same account (via the Subdomains tile in the portal, which creates the DNS record and a document root for you in one step), or an entirely separate application, even one hosted somewhere else.
SEO: why subdirectories usually win
Search engines have historically treated subdomains as separate entities from the root domain, closer to siblings than to sections of the same site. That's softened over the years, but subdirectories still concentrate your domain's backlinks, age, and topical authority in one place. A subdirectory blog benefits from every link pointing at your main domain. A subdomain blog largely has to earn its own authority from scratch, even though it shares your brand name.
This is why most sites keep blogs, help centers, and marketing pages in subdirectories (/blog, /help, /pricing) and reserve subdomains for things that are genuinely separate systems: app.yourdomain.com for a logged-in product, status.yourdomain.com for a status page hosted by a third party, mail.yourdomain.com for webmail.
When a subdomain is the right call
Subdomains make sense when the content can't reasonably live in the same install:
- Different software stack. Your main site is static, but you want a Node.js app or a different CMS for one section.
- Different server or provider entirely. A subdomain can point anywhere; a subdirectory generally can't unless the parent site is deliberately configured to reverse-proxy or rewrite into it.
- Isolation for security or performance. Keeping a high-traffic app separate from your marketing site so one doesn't affect the other.
- Third-party services that require it. Some platforms (help desks, status pages, e-commerce storefronts) only support a subdomain setup, sometimes with the root sent elsewhere. If you're pointing a subdomain at an outside platform like Shopify or Wix while keeping the rest of your domain and email on Flashcloud, see pointing your domain or subdomain to Shopify, Wix, and other services for the record types involved.
Setting up a subdirectory
If your site is WordPress, a subdirectory section is usually just a page or a category with a clean permalink structure, no server-level change needed. A genuinely separate application living at a path, not just a WordPress page, is a different case: it needs rewrite rules and extra maintenance most sites don't need. In practice, if two things need to be separate applications, it's usually easier and more reliable to give one of them a subdomain than to force a path-based split.
Setting up a subdomain
In the portal, open the hosting service and use the Subdomains tile. Creating a subdomain there sets up both the DNS record and a document root folder in the same step, so there's nothing separate to configure in DNS Zone Editor unless you want the subdomain to point somewhere other than your own hosting (an external app, a third-party platform, a different server). In that case, edit or add the record directly in DNS Zone Editor instead.
Whichever route you take, remember that a fresh subdomain needs its own SSL coverage and, if it's a new WordPress install, its own setup from scratch. Don't assume settings from your main site (PHP version, plugins, caching) carry over automatically. Each subdomain's document root is its own space.
A quick decision rule
Ask whether the new section shares your main site's software, database, and purpose. If yes, put it in a subdirectory and let it ride your domain's existing authority. If no, because it's a different app, a different vendor, or something that needs to scale or fail independently, give it a subdomain and treat it as its own small site with its own DNS entry.
If you're not sure which your existing setup already uses, or you want help mapping out a migration from one to the other without breaking existing SEO, open a ticket from the portal (Support → New ticket). Support can help you plan the move and check your DNS and redirects along the way.