Subdomain vs Subdirectory: Which Is Better for SEO?

Most sites should put a blog, help centre or content hub in a subdirectory such as example.com/blog/, and keep subdomains for sections that are genuinely separate, such as an app, a store on another platform or a staging copy. Google says it can crawl, index and rank both; the practical difference is how easily signals, analytics and maintenance stay in one place.

Google’s public position, repeated by its Search Advocates over many years, is that web search works fine with either structure, so the choice should follow how you run the site rather than a ranking trick. Both are crawled, indexed and ranked on their own merits.

The practical SEO difference is consolidation. Pages in a subdirectory share the main site’s internal links, navigation and history, so new content benefits from what the site has already earned. A subdomain can be treated more like its own site, which is useful when it really is a separate product, and a drag when it is just the company blog. Link the two clearly whichever you choose, and keep one canonical URL for every page with a canonical tag.

Avoid the myth that one structure is penalised. Sites rank well on both; teams that move content back and forth without redirects are the ones that lose traffic.

Use a subdomain when the section runs on a different platform, needs different security boundaries, or should not mix with the main site at all. A store on Shopify, a SaaS app, a staging copy and a status page are typical examples.

• Different stack: a CNAME record is usually all a hosted platform needs, whereas serving it at /shop/ would need a reverse proxy.
• Security isolation: cookies set for app.example.com are not sent to the marketing site, so a compromised plugin on the blog cannot read app sessions, unless cookies are deliberately set for the parent domain.
• Staging: staging.example.com keeps test copies off the live site; protect it with a password and a noindex rule.
• Separate audiences: a regional site with its own hosting or team can sit on its own host name.

Map every old URL to its new address with a 301 redirect before anything else changes, then update internal links, canonicals and the sitemap. Redirects are what carry visitors and search signals across; without them the move starts from zero.

# .htaccess on blog.example.in: send every path to example.in/blog/
RewriteEngine On
RewriteCond %{HTTP_HOST} ^blog\.example\.in$ [NC]
RewriteRule ^(.*)$ https://example.in/blog/$1 [R=301,L]

• Keep the old host name resolving and redirecting for at least a year.
• Use Search Console’s Change of Address tool only for whole-domain moves; a subdomain-to-folder move just needs redirects and a fresh sitemap.
• Expect recrawling to take weeks; watch the Pages report for redirect and 404 counts.

Redirect syntax and testing are explained in the .htaccess 301 redirect guide, and plugin-based redirects in WordPress 301 redirects.

Sources: Google Search Central documentation on site moves with URL changes, Change of Address, and Search Console domain properties; MDN documentation on the cookie Domain attribute.