Subdomain or Subfolder for a Blog?

Use a subfolder — yoursite.com/blog, not blog.yoursite.com — unless a technical or organisational constraint makes it impossible. Google says it handles both structures, and it does. The advantage of a subfolder is that it removes a judgement call entirely: every link the blog earns lands unambiguously on the same host as your commercial pages.

That's the short version, and for most sites it's the whole decision. The longer version is worth reading if you already run a subdomain, because the answer to "should I move it" is not automatically yes.

What Google actually says

Google's position has been consistent for well over a decade and it is genuinely neutral. John Mueller's summary: "Google Web Search is fine with using either subdomains or subdirectories… use what works best for your setup and think about your longer-term plans when picking one or the other."

He has also been more specific about the tie-breaker: "In general, we see these the same. I would personally try to keep things together as much as possible. So if it's the same site then try to put them on the same site… and use subdomains where things are really kind of slightly different" (Search Engine Journal).

Read carefully, that is not "it makes no difference." It's "we handle both, and we'd rather you kept related things together." Which is exactly the practitioner recommendation, arrived at from the other direction.

Why practitioners still prefer subfolders

The disagreement isn't really about whether Google can associate a subdomain with its parent. It's about whether you want to depend on it doing so.

A subdomain is technically a separate host. Google generally works out that blog.yoursite.com belongs to yoursite.com, and usually gets it right — but "usually gets it right" is a weaker position than "there is nothing to get right." With a subfolder:

Every link the blog earns is a link to the same host as your pricing page, with no inference required.
Internal links between blog posts and product pages are ordinary same-site links.
One Search Console property covers everything; one sitemap, one robots.txt, one set of Core Web Vitals.
There's no risk of the blog and the main site being evaluated as separate entities during a ranking or spam assessment.

None of those are enormous individually. Together they're a free option, and free options are worth taking.

There's a second-order effect too: backlink tools treat hosts differently from Google. If your blog earns the links and your product site gets the credit only in Google's eyes, your own reporting will understate what the blog is doing. Do subdomain links count as backlinks covers that measurement gap in detail.

The case studies, and how to read them

The subfolder camp's evidence is a set of before-and-after migrations. The best known is Moz's own testing, where Rand Fishkin reported moving content onto a subdomain and back again several times and seeing "a considerable boost in rankings and in search traffic" each time it came back to the main domain. Other widely-cited examples, collected by CognitiveSEO, show similar gains after consolidating subdomain content into subfolders.

Read those results with two caveats.

They're not controlled experiments. A subdomain-to-subfolder migration almost always ships alongside a content audit, better internal linking, and fresh attention on pages that had been neglected. Attributing the entire gain to the URL structure overstates the case.

They're mostly older. The strongest examples date from a period when Google was demonstrably worse at associating hosts. The gap has narrowed.

What survives the caveats is a consistent direction of travel: nobody reports moving to a subdomain and gaining. The downside risk is asymmetric, which is the practical argument for the subfolder default.

When a subdomain is the right answer

There are legitimate cases, and a constraint is a better reason than a preference.

A hosted blog platform you can't reverse-proxy. Some CMS and help-desk products only offer a CNAME to a subdomain. If subfoldering means an engineering project you won't actually staff, a working subdomain beats a theoretical subfolder.

A genuinely separate property. A community forum, a status page, a customer-facing app, or a user-generated content platform. These aren't your blog; they're different things that happen to share a brand.

Deliberate reputational separation. If the property carries spam or moderation risk you don't want associated with your main site, separation is the point.

Country or language targeting where the business is structured that way.

What isn't a good reason: "our developers said it's easier." It usually is easier, and it's usually a fifteen-minute proxy rule away from being unnecessary.

How to run a blog at /blog when your CMS lives elsewhere

This is the practical blocker for most teams, and it's solvable. A reverse proxy sits in front of your main domain and forwards requests for /blog/* to the blog platform, so the content is served under your primary host without moving it.

The common routes:

Your stack	How to do it
Cloudflare in front of the site	A Worker or rewrite rule routing `/blog/*` to the blog origin
Vercel or Netlify	A rewrite entry in `vercel.json` or `netlify.toml`
Nginx	A `location /blog/` block with `proxy_pass`
Most hosted CMS platforms	Built-in subdirectory hosting, often on higher tiers

Two details decide whether it works: the blog platform must emit relative or correctly-rewritten asset URLs, and its internal links and sitemap must reference the subfolder path rather than the original host. Get those wrong and you serve the same content at two addresses, which is a canonicalisation problem rather than a ranking one — what is a canonical tag explains how to resolve it if you end up there.

Moving an existing blog from subdomain to subfolder

If your blog already lives on a subdomain and performs well, migrating is a real project with real downside. Do it because the structure is causing a problem you can name, not because of a general claim that subfolders rank better.

If you do move:

Map every URL individually. blog.site.com/post-name to site.com/blog/post-name, one to one. Never a blanket redirect to /blog.
Use 301s, not 302s. What is a 301 redirect covers why the distinction matters.
File a Change of Address in Search Console. Moving between subdomains counts as a site move, and since June 2026 Google wants it filed from every verified variant.
Keep the subdomain resolving indefinitely. The redirects only work while it does.
Expect a wobble of several weeks. Does changing your domain name hurt SEO sets out the timeline, which applies to host changes too.

Either way, the blog's value comes from the links it earns. If yours is new, cold outreach is the hard road — a one-for-one exchange is the easier one. Backlinkster matches site owners who each want an in-content link and verifies both are live in code, with five swaps a month free.

Frequently asked questions

Is a subdomain or a subfolder better for a blog? A subfolder, in almost every case. Google says it handles both, but a subfolder removes any question about whether the blog belongs to the main site, keeps every earned link on the same host as your commercial pages, and consolidates your reporting into one property.

Does Google treat subdomains as separate sites? Sometimes. Google generally works out that a subdomain belongs to its parent domain, but it's an inference made case by case rather than a guarantee. A subfolder gives it nothing to infer.

Will moving my blog to a subfolder increase traffic? Possibly, but the published case studies bundle the URL change with content audits and internal-linking improvements, so the structural gain alone is smaller than the headline numbers suggest. If your subdomain blog performs well, the migration risk may outweigh the upside.

Can I host my blog on a subfolder if my CMS is a separate platform? Yes, via a reverse proxy — a Cloudflare Worker, a Vercel or Netlify rewrite, or an Nginx proxy_pass rule that routes /blog/* to the blog origin. Make sure the platform emits asset URLs and a sitemap that reference the subfolder path.

Do links from my own subdomain count as backlinks to my main site? Not meaningfully. Backlink tools will often report them as external links because the host differs, but Google understands you own both, so they carry roughly the weight of an internal link.

Does moving from a subdomain to a subfolder need a Change of Address request? Yes. Google treats a move between subdomains as a site move, and its current guidance asks you to file the request from every verified variant of the old host.

The bottom line

Default to a subfolder because it is the option with nothing to explain. Google's own advice is to keep related things together and reserve subdomains for content that is genuinely a different thing, which is the same conclusion the case studies reach by a noisier route. If a constraint forces a subdomain, use one and stop worrying — the penalty people fear does not exist. Just don't choose one for convenience when a fifteen-line proxy rule would have avoided the question entirely.