Subdomain vs subfolder for SEO is one of the longest-running arguments in the industry, and it survives because both sides have a point. Google’s official line is that it does not much matter. Many practitioners insist it does. The useful answer sits between them: Google handles both, but the two set-ups create different amounts of work, and that work is where sites slip.
What Google has said
The clearest statement comes from John Mueller in a Google SEO Snippets video, reported by Search Engine Roundtable on 24 January 2018: “Google web search is fine with using either subdomains or subdirectories.”
He did not stop there. He set out the practical differences, and they are worth more than the headline:
| Subfolder (example.com/blog/) | Subdomain (blog.example.com) | |
|---|---|---|
| Google’s view | Fine | Fine |
| Crawling | “Helps us with crawling since we understand that everything’s on the same server” | No such note from Google |
| Search Console | Covered by the main property | “You’ll need to verify subdomains separately” |
| Settings and reporting | Managed once, for the whole site | Changes to settings and performance tracking per subdomain |
| Common reason to choose it | Content that belongs to the main site | A separate platform, team or product that needs its own stack |
Why many SEOs still prefer subfolders
Plenty of experienced SEOs report that moving content from a subdomain into a subfolder improved its performance, and that new sections launched in subfolders did better than those launched on subdomains. That is practitioner experience, not a Google statement, and the reports rarely control for everything else that changed in the same migration.
It is still worth taking seriously, because there is a plausible mechanism that does not require Google to treat subdomains as second-class. A subfolder is part of the same site by default: the same navigation, the same internal links, the same property in Search Console, the same people looking after it. A subdomain is often a separate install that drifts. It gets fewer links from the main site, a different template, and nobody checking its reports. The structure does not hurt it. The neglect that comes with the structure does.
Subdomain vs subfolder for SEO: how to choose
Start from the content, not the URL. Ask whether the new section is part of the same site in the reader’s mind.
- A blog, guides or resources supporting your main topic. Use a subfolder. It belongs to the same site, and you want it linked into the same structure; see our post on internal linking for SEO.
- A separate application or tool. A subdomain is often the honest choice. It runs on different infrastructure, and it is not content you need ranking alongside your articles.
- A help centre on a hosted platform. If the platform only supports a subdomain, accept it and manage it properly rather than fighting it.
- A different language or market. Either can work; consistency and correct hreflang matter more than the choice itself.
Then ask who will maintain it. If the section will be written by the same team, published through the same CMS and promoted through the same newsletter, a subfolder keeps it inside the processes that already work. If it will be run by a different team on a different platform, a subdomain at least makes that separation visible, which is better than pretending it is one site when nobody treats it as one.
One more test: imagine the section succeeds. Would you want its links and attention to strengthen the main site, or does it stand on its own as a product? Content that should feed the rest of the site belongs in a subfolder. Software, logins and dashboards rarely need to rank at all.
If you use a subdomain, run it properly
Mueller’s own list of differences doubles as a checklist. Each item is something that gets forgotten:
- Verify it in Search Console. Either as its own property or through a domain property, so its coverage and performance are visible.
- Configure it. Settings, sitemaps and robots.txt apply per host. A subdomain without its own sitemap is relying on links alone.
- Track it. Report on it as its own site, so a drop does not hide inside the main domain’s numbers.
- Link to it. If the subdomain holds content you want found, link to it from the main site’s navigation and from relevant articles, and link back.
A well-run subdomain is a perfectly good home for content. A neglected one is where the “subdomains don’t rank” stories come from.
The real risk: changing your mind later
Mueller’s most practical advice is to pick “a set up that you can keep for longer”. Changes to URL structure take time to settle. Every move from subdomain to subfolder, or back, means redirecting every URL, updating internal links and waiting while search engines process the change.
If you do have to migrate, use permanent redirects mapped URL to URL, not a blanket redirect to the new homepage. Our guide to 301 vs 302 redirects covers which to use and the mistakes that cost traffic during a move. Expect fluctuation while it settles, and do not judge the result in the first week.
What this cannot settle
The limitation is that nobody outside Google can isolate the effect of the URL structure alone. Every subdomain-to-subfolder story comes bundled with other changes: new templates, new internal links, a fresh round of attention from the team. Google’s statement covers how it handles the two set-ups, not how your particular site will perform after a move, and no published figure can tell you that. Treat any case study that credits the URL change alone with the same caution you would give a single before-and-after screenshot: it shows what happened to one site, not why it happened.
So the practical rule is short. Put content that belongs to your site in a subfolder by default, because it is simpler to crawl, verify, link and report on as one site. Use a subdomain when there is a real technical or organisational reason, and then run it as a site in its own right. Whichever you choose, choose once. A good structure you keep beats a slightly better one you migrate to every two years.
If you are planning a new section to build topical coverage, our guide to building topical authority covers how to structure it, and the strategy archive collects the related technical posts.
Frequently asked questions
Does Google prefer subfolders over subdomains?
Not officially. John Mueller said Google web search is fine with using either subdomains or subdirectories.
Why do people say subfolders rank better?
Many SEOs report better results with subfolders. That is practitioner experience, not a Google statement, and it often reflects how subdomains are managed rather than how Google treats them.
Do subdomains need separate Search Console verification?
Yes. Mueller said you need to verify subdomains separately in Search Console and track performance per subdomain.
Should I move my blog from a subdomain to a subfolder?
Only with a clear reason. URL structure changes take time to settle, so weigh the migration cost and use permanent redirects mapped page to page.
The takeaway Google is fine with either. Default to a subfolder for content that belongs to your site, run any subdomain as its own property, and pick a structure you can keep.
