Subdomain vs Subfolder: Where Should Your Blog Live?

Either setup can work for Google Search: Google lists subdomains versus subdirectories among the things it believes you shouldn't focus on, so choose the one your blog platform supports and that you can keep for years. Switching later means moving every post to a new address. Below is what Google's documentation says, where blog.example.com and example.com/blog really differ, and a short list for choosing. The comparison uses Google's documentation as read on 8 October 2026; no ranking test was run for it.

What Google says about ranking

Google's SEO Starter Guide answers the question under the heading "Things we believe you shouldn't focus on". Its advice: "From a business point of view, do whatever makes sense for your business." It adds that a site may be easier to manage in subdirectories, while at other times it could be sensible to divide topics among subdomains, depending on what the site covers or the industry it is in (Google: SEO Starter Guide).

In Google's guide to its ranking systems, the only system described in terms of subdomains is site diversity. Google says it usually limits any one site to two web page listings in its top results, and that "Site diversity generally treats subdomains as part of a root domain" (Google: ranking systems guide). The same passage adds that subdomains are sometimes treated as separate sites when Google's systems judge it relevant.

So a blog on a subdomain generally doesn't earn your site extra places among the top results. What is a SERP shows what else shares a results page with those listings.

What practitioners say, and how it differs

Some SEO articles go further than Google does. Search Engine Journal's ranking-factor guide, for example, concludes it is "safe to assume Google treats subdomains as separate websites", reasoning that subdomains have to be verified separately in Search Console (Search Engine Journal). That is an inference, not a Google statement, and its premise no longer holds for every setup: since 2019, a single Search Console Domain property shows "data for all URLs under the domain name, including all protocols, subdomains, and paths" (Google: domain-wide data).

The accurate picture is mixed. Google treats a subdomain as its own host for some things and as part of your domain for others, and the comparison below lists which.

Where the two setups differ

• Ranking. Subdomain (blog.example.com): No advantage stated by Google. Subfolder (example.com/blog): No advantage stated by Google.

• Site diversity. Subdomain (blog.example.com): Generally counted with the root domain; sometimes treated as a separate site. Subfolder (example.com/blog): Part of the same site.

• Site name in results. Subdomain (blog.example.com): Can have its own site name. Subfolder (example.com/blog): Shown under the main site's name.

• robots.txt. Subdomain (blog.example.com): Only a file at the subdomain's root applies. Subfolder (example.com/blog): Covered by the main site's file.

• Search Console. Subdomain (blog.example.com): Included in the Domain property for example.com, or its own URL-prefix property. Subfolder (example.com/blog): Included in the same Domain property, or a URL-prefix property for the folder.

• Setup on Ghost(Pro), as one hosted platform. Subdomain (blog.example.com): A CNAME record in your DNS. Subfolder (example.com/blog): A Business plan add-on plus a reverse proxy on your main site.

• Moving later. Subdomain (blog.example.com): A site move with new URLs for every post. Subfolder (example.com/blog): The same.

Site names and robots.txt

Two of Google's host-level rules treat a subdomain as its own site. Google shows a site name with each result, and it supports site names for domains and subdomains only: "Google Search does not support site names at the subdirectory level" (Google: site names). A blog at example.com/blog appears under the main site's name; a blog at blog.example.com can show a name of its own.

robots.txt, the file that tells crawlers which paths they may fetch, works per host as well. Google's guide says "A robots.txt file applies only to paths within the protocol, host, and port where it is posted", and rules in the main domain's file don't apply to its subdomains (Google: create a robots.txt file, Google: robots.txt specification). Crawl rules for a subdomain blog must sit in a file at the subdomain's root, which a hosted platform may manage for you; a subfolder blog follows the main site's.

Measuring the blog in Search Console

Both setups are easy to measure, so this criterion rarely decides the question. A Domain property "aggregates data for all subdomains, protocols, and subpaths of the property", and it needs DNS verification unless the site is hosted on a Google product like Blogger (Search Console Help: add a property). To see the blog alone, add a URL-prefix property for its address, such as https://blog.example.com/ or https://example.com/blog/, or filter the Performance report by page. How to check your website's SEO performance shows what to compare once the data is there.

Setting up a separate blog platform

The practical difference is often setup. If your main site runs on one system and your blog on a hosted platform, a subdomain can point straight at the platform with a DNS record. A subfolder means your main site must pass blog requests through to the platform, a setup called a reverse proxy. Ghost(Pro) documents both: for a custom domain it recommends a subdomain rather than a root domain "for a quick and easy setup" (Ghost: custom domains), while "Subdirectory and proxy setups are a paid add-on for our Business plan and require a specific custom Nginx or Apache configuration" (Ghost: subdirectory setup). Check your own platform's documentation and plan before you decide.

Moving later

Switching from one setup to the other changes the address of every post, which Google treats as a site move with URL changes. Its guide warns: "Expect temporary fluctuation in site ranking during the move", and says a small to medium-sized site "can take a few weeks for most pages to move" (Google: site moves). If you ever need to switch, follow that guide; the cheaper path is to choose well at the start.

Which to choose

• The blog runs on the same system as the rest of your site. Choose: Subfolder. Why: It is already part of the site: one name in results, one robots.txt.

• The blog runs on a hosted platform whose plan has no subdirectory option. Choose: Subdomain. Why: It connects with a DNS record, and Google states no ranking advantage either way.

• The blog is a separate publication with its own name. Choose: Subdomain. Why: It can show its own site name in results.

• The blog already lives on one of them. Choose: Keep it. Why: Moving changes every post's address and brings temporary ranking fluctuation.

Your next step

Look up what your blog platform supports, and on which plan, before you register anything. If a subfolder needs a proxy you can't run, use a subdomain and measure it within a Domain property in Search Console. If you are still choosing the domain itself, read does your domain name affect SEO, and for the basics a new blog is judged on, start with what is SEO.