Subdomain vs Subdirectory

TL;DR — A subdomain is blog.example.com (a prefix before your domain). A subdirectory (or subfolder) is example.com/blog/ (a path after it). You’ll hear that subdirectories are “better for SEO.” They’re not, inherently — Google says either can work. Subdirectories are often easier to run as one application and analytics scope, so unless you have a real reason to split things out, keeping everything together is the simpler choice.

What’s the difference?

It comes down to where the extra word goes relative to your domain:

• Subdomain — the word comes before your domain, joined by a dot: blog.example.com, shop.example.com, support.example.com. Technically this is a separate address, so it can live on a different server or run a different system (CMSA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms.).
• Subdirectory (also called a subfolder) — the word comes after your domain, joined by a slash: example.com/blog/, example.com/shop/. It’s always part of the same address as your main site.

Does it matter for SEO?

Here’s the honest answer most articles won’t give you: not as much as people claim. Google has said for years that it has no preference. Both can work fine.

The reason you see headlines like “we moved to a subfolder and traffic jumped 40%” is that those moves almost never happen on their own. When a team migrates a blog, they usually also improve internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., delete weak pages, and upgrade the platform — all at the same time. Those changes are what move traffic. The URL structure mostly went along for the ride. (I dig into this in the Advanced tab.)

So which should you pick?

A simple rule of thumb:

• Use a subdirectory for things closely tied to your main site — a blog, a help center, docs. It keeps routing, analytics, and content management under one roof. A Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. Domain property can aggregate subdomains too, so property count is not the deciding factor.
• Use a subdomain when something is genuinely separate — a different product, a different team or server, or country-specific versions of your site. There’s nothing wrong with a subdomain; it just takes a little more setup to manage.

The thing most people get wrong

Don’t migrate a working subdomain to a subdirectory just because someone told you subfolders rank better. If your subdomain blog is doing well and is well-linked from your main site, moving it is risk with little reward. Migrations always carry the chance of losing rankings during the transition. Want the full reasoning, the case studies, and what Google and Bing actually say? Switch to the Advanced tab.

TL;DR — Subdomains and subdirectories are both viable for search, but they are operationally different. Google evaluates per site whether a subdomain is treated as part of your site or as a separate entity — the deciding factor is integration (internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., consistent UX, related content), not the dot-vs-slash. The case studies showing big gains from subdomain→subdirectory moves are almost always confounded: better internal linkingLinks between pages on the same site., content pruning, a CMSA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms. upgrade, or analytics changes rode along. My position: don’t migrate for URL structureURL structure is how the parts of a web address — scheme, domain, path, query string, and fragment — are organized and formatted. It mostly affects crawling, usability, and how engines understand a page, not rankings directly. alone — the risk usually outweighs the upside. Subdirectories can carry operational advantages (shared routing, analytics, and publishing systems), but those are convenience wins, not a ranking edge. Bing’s concern is subdomain abuse (leasing, PBNs), not legitimate subdomain use. And per Google’s November 2024 site-reputation-abuse policy, moving content between structures doesn’t fix a spam violation.

What they actually are

A subdomain is a prefix before the root domain, separated by a dot — blog.example.com. It’s technically a separate hostname, so it can point at a different server, run a different CMS, and be owned by a different team. A subdirectory (subfolder) is a path segment after the domain, separated by a slash — example.com/blog/. It’s always the same hostname, and so the same “site” from a crawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor. and analytics standpoint. There’s a third option for international work — a ccTLDCountry-code top-level domain like .de or .co.uk — a strong geotargeting signal. like example.de — which is always treated as a separate site.

What Google actually says (and what it means)

Google’s official documentation is blunt: “You should choose whatever is easiest for you to organize and manage. From an indexingStoring a crawled page in the search index so it can appear in results. Crawled is not the same as indexed — Google selects what to keep, and indexing isn't guaranteed. and ranking perspective, Google doesn’t have a preference.” That’s the headline — no blanket advantage either way.

The nuance is more important than the headline. John Mueller has said, “In general, we see these the same,” but added that he’d “personally try to keep things together as much as possible.” The key word is personally — that’s a preference for operational simplicity, not a statement that subdirectories rank better.

The deepest point Mueller has made is that there’s no blanket rule at all: “sometimes that can include sub-domains, sometimes that doesn’t include sub-domains. Sometimes that includes sub-directories, and sometimes that doesn’t include specific sub-directories.” In other words, Google decides per site whether a subdomain (or even a subdirectory) is treated as part of the main site. The signals it uses are integration signals: internal linking between the section and the root, consistent branding and UX, thematically related content, and a coherent sitemapA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing. structure.

Gary Illyes confirmed the flip side at Pubcon 2023: subdirectories can be treated as separate sites too — “It’s not common on the English web but it is in other languages.” So the structural choice isn’t the lever people think it is; the integration is.

My position: the “wins” are usually confounded

I wrote the contrarian take on this for Ahrefs in March 2021, and I’ll restate it here because it still holds. The belief that subdirectories are SEO-superior rests on case studies that move a section from a subdomain to a subfolder and report a traffic jump. The problem is that those migrations almost never change only the URL.

When teams do these moves, they typically also:

• Improve internal linking — the section gets properly woven into the main nav and contextual links for the first time.
• Prune or rewrite thin contentThin content is web content that provides little or no value to users. Google's spam policies name it 'thin content with little or no added value' — and it's about value per page, not word count. as part of the migration.
• Upgrade the CMS or platform, which often improves speed, templates, and crawlabilityCrawlability is how well search engine crawlers can discover, access, and fetch a site's pages. A crawlability issue is any technical condition — blocked access, broken links, server failures, or bloated URL inventory — that stops pages from reaching the index..
• Fix analytics, so traffic that was always there is finally measured under one property (cross-domain/cross-host tracking gaps are common on subdomains).

Any one of those can move traffic. Attribute the whole gain to the dot-becoming-a-slash and you’ve confused correlation with causation. As I put it in the article: changes introduce risk, so think twice before changing from a subdomain to a subdirectory if the only reason you’re doing it is for SEO.

That doesn’t mean no case study isolates the structure. Pink Cake Box is the cleanest one I know of — Archive.org checks show no design or content changes accompanied the move, and organic sessions rose roughly 40%. The reverse test, IWantMyName moving subdirectory→subdomain and dropping about 47%, adds weight. I take those seriously. But they’re the exceptions that get clean measurement; the HotPads/HubSpot-style cases everyone cites had simultaneous changes, and the people who ran them (John Doherty on HotPads) have said as much. Correlation studies — the “11.8M results” and similar — are correlational by nature; sites that use subdirectories also tend to be larger and more SEO-mature.

Real technical differences (these are not myths)

Set the ranking debate aside — there are concrete operational differences, and they usually favor subdirectories for closely-related content:

• Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results.. A subdomain needs separate verification and its own property. (A GSC Domain property covers all subdomains at once, which softens this.) Mueller: “We do have to learn how to crawl them separately but for the most part that’s just a formality for the first few days.”
• CrawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor.. With a subdirectory, GooglebotGooglebot is Google's web crawler — the software that fetches pages so Google can index and rank them. It comes in two variants, Googlebot Smartphone (primary, under mobile-first indexing) and Googlebot Desktop, and runs an evergreen Chromium renderer. already understands it’s the same server — no re-learning period. Mueller framed the subdirectory advantage as: “this helps us with crawling since we understand that everything is on the same server and can crawl it in a similar way.”
• Analytics. One GA4 property by default; no cross-domain/host configuration to capture the section’s traffic.
• Site names in search results. Google supports site names for domains and subdomains but not for subdirectories — a real, documented functional difference.
• Preferred Sources / property-level tools. Some Search ConsoleGoogle's free tool for monitoring crawling, indexing, and search performance. surfaces operate at domain and subdomain level, not subdirectory level.
• Link equity. Backlinks to a subdirectory are unambiguously under the root domain. For a subdomain, whether that equity “flows” to the root depends on whether Google treats the subdomain as part of your site — the same per-site evaluation as everything else.

When a subdomain genuinely makes sense

Subdomains aren’t a mistake. Reach for one when:

• It’s a genuinely separate product or service — app.example.com, status.example.com, community.example.com.
• You need technical separation — a different CMS, a different stack, a different team, or different infrastructure that’s far easier to run on its own hostname.
• International targeting — Google lists subdomains (de.example.com), subdirectories (example.com/de/), and ccTLDs (example.de) as equally valid for geotargetingConfiguring a site or URL to target users in a specific country.. Subdirectories are operationally simplest; ccTLDs send the strongest geoGenerative Engine Optimization — visibility inside AI answer engines.-signal; subdomains sit in the middle.
• Large enterprises with multiple business units, where separate GSC properties per team is a feature, not a bug.

What Bing cares about

Bing doesn’t prescribe one structure for legitimate sites. In “Some Thoughts on Website Boundaries” (Frederic Dubut and the Bing Webmaster ToolsMicrosoft's free portal for monitoring and improving how a site appears in Bing search — the peer to Google Search Console, plus IndexNow instant indexing, richer backlink data, and keyword volumes. Because Bing's index also feeds Microsoft Copilot, it doubles as a window into AI-search visibility. team, November 2019), Bing’s concern is inorganic site structure — PBNs, doorways, and subdomain/subfolder leasing, where third-party content is hung off a subdomain with minimal internal linking specifically to leak site-level signals to an unrelated party. Bing’s blunt warning: “If you offer free hosting on your subdomains and 95% of your subdomains are flagged as spam, Bing will expand penalties to the entire domain, even if the root website itself is not spam.” For a normal business using its own subdomain, none of this applies.

This connects to Google’s site reputation abuse policy update (November 2024), which is worth knowing: “Moving content to a subdirectory or subdomain within the same site’s domain name doesn’t resolve the underlying issue and may be viewed as an attempt to circumvent spam policy.” So you can’t structure your way out of a parasite-SEO problem.

The reverse-proxy workaround

If you’re technically locked into a subdomain — WordPress.com, a headless CMSA content management system that separates the content repository from the presentation layer, delivering content via API to any front-end framework rather than rendering HTML server-side itself. It doesn't specify the rendering mode, hosting, cache, preview security, or publishing workflow — those are separate decisions., or a docs/help platform you can’t self-host — you don’t have to migrate to get a subdirectory URL. You can use a reverse proxy (Cloudflare WorkersA serverless function that runs at Cloudflare's global edge, close to every user. is the common route) to serve blog.example.com as example.com/blog/ from the crawlerA crawler — also called a spider or bot — is an automated program that fetches web pages, extracts their links, and queues new URLs to visit. Search engines use crawlers to discover and download content for their index.’s and user’s perspective. The URL everyone sees is the subdirectory path; the backend stays on the subdomain install. Cloudflare documents this pattern in a two-part Workers series. It’s a legitimate, widely-used technique — just be sure the proxied content is genuinely yours, not leased (see the abuse policies above).

Should you migrate? How to think about the risk

My decision rule:

• Stay put if your subdomain is established, ranking, well-linked from the root, and integrated. Migrating purely for URL structureURL structure is how the parts of a web address — scheme, domain, path, query string, and fragment — are organized and formatted. It mostly affects crawling, usability, and how engines understand a page, not rankings directly. is risk with little reward.
• Migrate when you’re doing a larger platform migration anyway, or the subdomain has real technical/performance problems — i.e., when the URL change is bundled with fixes that actually move the needle.
• If you do migrate, fix the confounders first so you can read the result cleanly: internal linking, content quality, redirectsA redirect sends browsers and crawlers from a requested URL to a different one. An HTTP redirect specifically is a 3xx status code paired with a Location header; meta refresh and JavaScript redirects achieve a similar navigation without being a 3xx response themselves. Permanent redirects (301/308) are Google's signal the target should be canonical; temporary ones (302/303/307) aren't. (301s), and analytics. Then the structure change is the only variable left.
• Follow Google’s official site-move workflow — map old URLs to new ones, redirect every one of them, update internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them. and sitemapsA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing., verify the new property in Search Console, and then monitor a representative set of URLs rather than assuming the move went cleanly.

TIP Find legacy subdomain URLs the migration map missed

Unmatched URLs, weak matches, many-to-one mappings, chains, and sitemap removals are migration defects to resolve before launch. The tool does not decide whether the subdomain move itself is worthwhile.

Review the URL map with my free SEO Migration Planner & Validator Free

1. Supply the legacy subdomain inventory and proposed subdirectory destinations.
2. Resolve unmatched, weak, many-to-one, chained, and sitemap-only mappings before release.
3. Crawl the staged map, launch only after approval, then monitor representative URLs and indexation during processing.

Tap to enlarge

The review table maps old.example.com/products/widget-a exactly to new.example.com/products/widget-a and marks it accept. The retired-campaign URL has no safe match and remains todo.

Expect 2–4 weeks of fluctuation as Google processes redirects, with recovery typically inside 4–6 weeks when the migration is done correctly.

Where this fits

This is one piece of how you organize a site — siblings in this cluster cover URL structure conventions, site architectureSite architecture is how a website's pages are organized, categorized, and interlinked. It controls how crawlers discover pages, how link equity flows, and how clearly search engines understand each page's topical context. Silo structure, hub and spoke, and topic clusters are the three common models. and crawl depthCrawl depth usually means click depth — how many clicks it takes to reach a page from the homepage by following internal links. It can also mean a crawler setting that limits how many levels deep a crawl goes before it stops., and faceted navigationFaceted navigation (faceted search, product filtering) lets visitors refine a list of products or content by attribute — price, color, size, brand, rating. The SEO problem: each filter combination can spawn a distinct crawlable URL, turning a small catalog into millions of near-duplicate pages that waste crawl budget and dilute ranking signals., and the international angle overlaps with hreflangHreflang is an annotation (in HTML, HTTP headers, or XML sitemaps) that tells search engines which language and optional region a page targets, and which alternate versions exist. It only works when every page in the cluster references all the others. and ccTLD decisions in international SEOInternational SEO is the practice of optimizing a site so search engines understand which countries and/or languages it targets, and serve the right version to each user. It spans URL structure, hreflang, and on-page localization.. The throughline is the same: structure is a way to organize and manage content, not a ranking lever in its own right.

AI summary

A condensed take on the Advanced version:

• Subdomain = blog.example.com (separate hostname). Subdirectory = example.com/blog/ (path on the same hostname). ccTLDCountry-code top-level domain like .de or .co.uk — a strong geotargeting signal. = example.de (always a separate site).
• Google has no blanket preference. Official docs: choose what’s easiest to manage; “Google doesn’t have a preference” for indexingStoring a crawled page in the search index so it can appear in results. Crawled is not the same as indexed — Google selects what to keep, and indexing isn't guaranteed./ranking.
• Treatment is per-site. Mueller: sometimes subdomains are treated as part of the site, sometimes not — and the same for subdirectories. The deciding factor is integration (internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., consistent UX, related content), not dot-vs-slash. Illyes confirmed subdirectories can be treated separately too.
• Patrick’s position: migration “wins” are usually confounded — better internal linkingLinks between pages on the same site., content pruning, CMSA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms. upgrades, or fixed analytics ride along with the URL change. Don’t migrate for URL structureURL structure is how the parts of a web address — scheme, domain, path, query string, and fragment — are organized and formatted. It mostly affects crawling, usability, and how engines understand a page, not rankings directly. alone; the risk outweighs the upside.
• Cleanest case studies: Pink Cake Box (+~40%, no other changes) and the IWantMyName reverse move (−~47%). Most other cited cases had simultaneous changes.
• Real (non-ranking) differences: subdomains need separate GSCA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. verification; site names in search work for subdomains but not subdirectories; subdirectories crawl without a re-learning period and use one analytics property.
• Bing targets subdomain abuse (leasing, PBNs), not legitimate subdomain use.
• Nov 2024 site reputation abuse: moving content between subdomain and subdirectory does not fix a spam violation.
• Reverse proxy (Cloudflare WorkersA serverless function that runs at Cloudflare's global edge, close to every user.) can serve a subdomain as a subdirectory URL if you’re technically locked into a subdomain.

Official documentation

Primary-source documentation from the search engines.

Google

• URL structure best practices — Google’s guidance on URLs; recommends ccTLDsCountry-code top-level domain like .de or .co.uk — a strong geotargeting signal. or subdirectories for geotargetingConfiguring a site or URL to target users in a specific country., no stated preference for domestic content.
• Managing multi-regional and multilingual sites — the three equivalent URL options for international targeting (ccTLD, subdomain, subdirectory) with their pros and cons.
• Site names in Google Search — site namesWebSite schema (schema.org/WebSite) is structured data — usually JSON-LD on the homepage — that identifies your domain as a website entity via its name and URL. Today it mainly feeds Google's Site Names feature; the Sitelinks Search Box it used to enable was discontinued by Google in November 2024. are supported for domains and subdomains but not subdirectories.
• Consolidate duplicate URLs — canonicalizationHow search engines pick one canonical URL among duplicates and consolidate signals onto it. methods (redirectsA redirect sends browsers and crawlers from a requested URL to a different one. An HTTP redirect specifically is a 3xx status code paired with a Location header; meta refresh and JavaScript redirects achieve a similar navigation without being a 3xx response themselves. Permanent redirects (301/308) are Google's signal the target should be canonical; temporary ones (302/303/307) aren't., rel="canonical", sitemapsA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing.); relevant when migrating between structures.
• Site move with URL changes — Google’s official workflow for a URL-structure migration: mapping, redirects, Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. verification, and monitoring.
• Site reputation abuse policy (November 2024) — moving content between a subdirectory and subdomain doesn’t resolve a spam violation.
• Subdomains and subdirectories (January 2008) — the oldest official Google blog treatment of the topic.

Bing / Microsoft

• Some Thoughts on Website Boundaries — Frederic Dubut and the Bing Webmaster ToolsMicrosoft's free portal for monitoring and improving how a site appears in Bing search — the peer to Google Search Console, plus IndexNow instant indexing, richer backlink data, and keyword volumes. Because Bing's index also feeds Microsoft Copilot, it doubles as a window into AI-search visibility. team on single-domain / subdomain / subdirectory models and the “inorganic site structureWebsite structure (site architecture) is a site's visible hierarchy, navigation, breadcrumbs, and URL organization — how pages relate and how people and search engines move between them. Internal linking is the primary signal Google reads to understand that structure, not URL folders.” penalty (PBNs, doorways, subdomain leasing).
• Bing Webmaster Guidelines — general guidance; no prescriptive preference between structures for standard sites.

Quotes from the source

On-the-record statements from Google and Bing. Where the source page supports it, each link is a deep link that jumps to the quoted passage.

Google — no preference

• “You should choose whatever is easiest for you to organize and manage. From an indexingStoring a crawled page in the search index so it can appear in results. Crawled is not the same as indexed — Google selects what to keep, and indexing isn't guaranteed. and ranking perspective, Google doesn’t have a preference.” — Google Search Central documentation.

John Mueller, Google (Office Hours Hangout, May 25, 2018; reported by Search Engine Journal)

• “In general, we see these the same. I would personally try to keep things together as much as possible.” Coverage
• “So if it’s the same site then try to put them on the same site, essentially, and use subdomains where things are really kind of slightly different.” Coverage
• “There are lots of really strong opinions on this so, from my point of view, this is something that could go either way.” Coverage

John Mueller, Google (on per-site treatment)

• “sometimes that can include sub-domains, sometimes that doesn’t include sub-domains. Sometimes that includes sub-directories, and sometimes that doesn’t include specific sub-directories.”

John Mueller, Google (on crawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor. and Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results., via Search Engine Journal)

• “this helps us with crawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor. since we understand that everything is on the same server and can crawl it in a similar way. Sometimes, it also makes it easier for users who recognize that these sections are all a part of the same bigger website.” Coverage
• “You’ll need to verify subdomains separately in Search ConsoleGoogle's free tool for monitoring crawling, indexing, and search performance.… We do have to learn how to crawl them separately but for the most part that’s just a formality for the first few days.” Coverage

Gary Illyes, Google (Pubcon 2023, on whether subdirectories can be treated separately — cited in my Ahrefs article)

• “Yes. It’s not common on the English web but it is in other languages.” Source

Matt Cutts, Google (former head of webspam)

• “They are roughly the equivalent. I would basically go with whichever is easier for you in terms of configuration, your CMSsA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms..” (2013)

Google — site reputation abuse (November 2024 policy update)

• “Moving content to a subdirectory or subdomain within the same site’s domain name doesn’t resolve the underlying issue and may be viewed as an attempt to circumvent spam policy.” Jump to quote

Bing — inorganic site structureWebsite structure (site architecture) is a site's visible hierarchy, navigation, breadcrumbs, and URL organization — how pages relate and how people and search engines move between them. Internal linking is the primary signal Google reads to understand that structure, not URL folders. (Frederic Dubut & Bing Webmaster ToolsMicrosoft's free portal for monitoring and improving how a site appears in Bing search — the peer to Google Search Console, plus IndexNow instant indexing, richer backlink data, and keyword volumes. Because Bing's index also feeds Microsoft Copilot, it doubles as a window into AI-search visibility. team, November 4, 2019)

• “If you offer free hosting on your subdomains and 95% of your subdomains are flagged as spam, Bing will expand penalties to the entire domain, even if the root website itself is not spam.” Jump to quote

Choosing (or migrating) a structure — checklist

Deciding where a new section should live

• Is the content closely related to the main site (blog, docs, help center)? → lean subdirectory.
• Does it need a separate CMSA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms., server, team, or stack? → a subdomain is reasonable.
• Is it a genuinely distinct product or service (app., status.)? → subdomain.
• International targeting? → subdirectory, subdomain, and ccTLDCountry-code top-level domain like .de or .co.uk — a strong geotargeting signal. are all valid; pick on operational cost vs. geoGenerative Engine Optimization (GEO) is the practice of optimizing content and brand presence so AI-powered search engines and assistants — Google AI Overviews, ChatGPT, Perplexity — cite, recommend, or mention you when generating answers. Google's position is that it's still SEO.-signal strength.
• Do you need site namesWebSite schema (schema.org/WebSite) is structured data — usually JSON-LD on the homepage — that identifies your domain as a website entity via its name and URL. Today it mainly feeds Google's Site Names feature; the Sitelinks Search Box it used to enable was discontinued by Google in November 2024. in search for this section? → only subdomains qualify, not subdirectories.

Before migrating subdomain → subdirectory (only if there’s a real reason)

• Confirm the move isn’t purely for SEO — if it is, reconsider.
• Fix internal linkingAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., content quality, and analytics first, so you can read the result cleanly and aren’t just confounding the test.
• Map every old URL to its new path and set 301 redirectsA redirect sends browsers and crawlers from a requested URL to a different one. An HTTP redirect specifically is a 3xx status code paired with a Location header; meta refresh and JavaScript redirects achieve a similar navigation without being a 3xx response themselves. Permanent redirects (301/308) are Google's signal the target should be canonical; temporary ones (302/303/307) aren't..
• Update internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., sitemapsA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing., and canonical tagsA rel=\"canonical\" annotation — in the HTML <head> or an HTTP Link header — that tells search engines which URL is the preferred version of duplicate or near-duplicate content. to the new paths.
• Verify the new structure in Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. (or use a Domain property).
• Don’t migrate to escape a site-reputation-abuse problem — it won’t fix it.
• Expect 2–4 weeks of fluctuation; monitor rankings and crawl statsA Google Search Console report (under Settings) that shows how Google has crawled your site over the last 90 days — total requests, download size, and average response time, broken down by response code, file type, Googlebot type, and purpose. It's only available for root-level properties (a Domain property or a URL-prefix property verified at the site's root). through recovery (typically 4–6 weeks).

If you’re locked into a subdomain

• Consider a reverse proxy (e.g., Cloudflare WorkersA serverless function that runs at Cloudflare's global edge, close to every user.) to serve it as a subdirectory URL instead of a full migration.
• Make sure the proxied content is genuinely yours, not leased third-party content.

The mental models

1. Structure is organization, not a ranking lever. The dot-vs-slash choice is about how you organize and manage content. Google has no blanket preference. Start every conversation here — it kills 90% of the bad advice.

2. Treatment is per-site, decided by integration. Google decides per site whether a subdomain is “part of you” or separate. The signals are integration: internal linkingAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., consistent UX, related content, coherent sitemapsA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing.. A well-integrated subdomain behaves like part of your site; a poorly-integrated subdirectory can behave like a separate one. Optimize the integration, not the URL.

3. The confounder test. Before you believe any “we moved and traffic jumped” story, ask: what else changed? Internal linksAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., pruned content, new CMSA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms., fixed analytics — if any moved at the same time, you can’t credit the URL structureURL structure is how the parts of a web address — scheme, domain, path, query string, and fragment — are organized and formatted. It mostly affects crawling, usability, and how engines understand a page, not rankings directly.. The only clean tests are the ones where nothing else changed (Pink Cake Box).

4. Convenience vs. capability. Subdirectories win on convenience (one GSCA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. property, one analytics setup, no crawl re-learning). Subdomains win on capability (separate stacks/teams/servers, site namesWebSite schema (schema.org/WebSite) is structured data — usually JSON-LD on the homepage — that identifies your domain as a website entity via its name and URL. Today it mainly feeds Google's Site Names feature; the Sitelinks Search Box it used to enable was discontinued by Google in November 2024. in search, clean separation for distinct products). Decide on which axis your situation actually lives.

5. The migration risk rule. Migrate only when the URL change is bundled with changes that genuinely move the needle, or when there’s a real technical problem. A working, well-integrated subdomain

• “subfolders rank better” is not a reason to migrate — it’s risk without reward.

Should this section use a subdomain or subdirectory?

Structure decisions that confuse cause and effect

Migrating only because subdirectories supposedly rank better

Google does not express a blanket ranking preference. Keep a healthy, integrated section where it is unless a real platform, product, or operating need justifies the risk of changing every URL.

Changing URLs, CMS, content, links, and analytics together

A bundled release makes the outcome impossible to attribute. Fix known content and linking problems first, document the baseline, and isolate changes where practical.

Treating a subdomain as unrelated in the site’s own navigation

Technical separation does not require user or link isolation. Give a legitimate subdomain clear contextual and navigational links so its relationship to the main site is understandable.

Check a migration sample from the command line

Put one old subdomain URL per line in old-urls.txt, then inspect the first response and destination on macOS or Linux:

while IFS= read -r url; do printf '%s\t' "$url"; curl -sS -o /dev/null -w '%{http_code}\t%{redirect_url}\n' "$url"; done < old-urls.txt

PowerShell equivalent:

Get-Content old-urls.txt | ForEach-Object { try { $r = Invoke-WebRequest -Uri $_ -MaximumRedirection 0 -SkipHttpErrorCheck; [pscustomobject]@{Url=$_; Status=$r.StatusCode; Location=$r.Headers.Location} } catch { [pscustomobject]@{Url=$_; Error=$_.Exception.Message} } }

The first hop should be a permanent redirectA 301 redirect is the HTTP status code for a permanent move: it tells browsers and search engines a URL has moved for good, and it's the strongest signal for consolidating a page's ranking signals onto the new URL. Google says permanent redirects don't cause a loss in PageRank. to the exact mapped subdirectory URL, not a home page or a chain. Run a full crawlerA crawler — also called a spider or bot — is an automated program that fetches web pages, extracts their links, and queues new URLs to visit. Search engines use crawlers to discover and download content for their index. and migration review before treating a sample as complete evidence.

Tools for a structure decision and migration

• SEO Migration Planner & Validator — build and review the old-to-new URL map, verify deployed redirectsA redirect sends browsers and crawlers from a requested URL to a different one. An HTTP redirect specifically is a 3xx status code paired with a Location header; meta refresh and JavaScript redirects achieve a similar navigation without being a 3xx response themselves. Permanent redirects (301/308) are Google's signal the target should be canonical; temporary ones (302/303/307) aren't., and compare sitemapA sitemap is a file that lists the pages, images, videos, and other files on your site so search engines can discover them. It helps discovery, but submitting a sitemap doesn't guarantee crawling or indexing. sets when a move is genuinely justified.
• Redirect Chain Mapper — trace whether an old subdomain URL reaches its matching subdirectory destination in one clean hop.
• Google Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. — use a Domain property for a combined view and hostname-specific properties when teams need separate operational reporting.
• A link crawlerA crawler — also called a spider or bot — is an automated program that fetches web pages, extracts their links, and queues new URLs to visit. Search engines use crawlers to discover and download content for their index. — compare navigation, inlinks, canonicals, and crawl depthCrawl depth usually means click depth — how many clicks it takes to reach a page from the homepage by following internal links. It can also mean a crawler setting that limits how many levels deep a crawl goes before it stops. before and after the change so improved integration is not mistaken for a URL-format win.

Test yourself: Subdomain vs Subdirectory

Five quick questions on how subdomains and subdirectories really differ for SEO. Pick an answer for each, then check.

Resources worth your time

My related writing

• Subdomain vs Subdirectory: Subdirectories Are Not Better Than Subdomains For SEO — my full contrarian case, with the Mueller and Illyes quotes, the case-study confounders, and why I’d think twice before migrating for URL structureURL structure is how the parts of a web address — scheme, domain, path, query string, and fragment — are organized and formatted. It mostly affects crawling, usability, and how engines understand a page, not rankings directly. alone.
• The Beginner’s Guide to Technical SEO — where site structureWebsite structure (site architecture) is a site's visible hierarchy, navigation, breadcrumbs, and URL organization — how pages relate and how people and search engines move between them. Internal linking is the primary signal Google reads to understand that structure, not URL folders. decisions fit in the bigger picture.

My speaking

• How Search Works (SlideShare) — my walkthrough of crawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor., renderingTurning HTML, CSS, and JavaScript into the final visual page and DOM., indexingStoring a crawled page in the search index so it can appear in results. Crawled is not the same as indexed — Google selects what to keep, and indexing isn't guaranteed., and ranking; useful background for why “integration” matters more than the URL. (Standing disclaimer applies: “This is my understanding of systems… not going to be 100% complete or accurate.”)

From around the industry

• Google’s John Mueller On When To Use Subdomain vs. Directory (Search Engine Journal, Matt G. Southern) — the May 2018 Office Hours quotes in context.
• Subdomains vs. Subfolders: Which Is Better for SEO & Why? (Search Engine Journal, Roger Montti) — Mueller on crawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor. and Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. treatment.
• Some Thoughts on Website Boundaries (Bing, Frederic Dubut) — Bing’s website-boundary models and the inorganic-site-structure penalty.
• Does Switching From a Subdomain to a Subfolder Improve SEO? Case Studies & Experts RoundUp (cognitiveSEO) — the best case-study roundup, honest about confounders.
• Subdirectories vs Subdomains: Which is Better for SEO? (Portent) — solid methodology and the Pink Cake Box / Archive.org verification.
• Subdomains vs Subdirectories Research: 20K Keywords Analysed (SE Ranking) — a transparent correlational study across 15 markets and 1.5M SERP positions.
• SEO Best Practices with Cloudflare Workers, Part 1: Subdomain vs. Subdirectory (Cloudflare) — the reverse-proxy workaround explained, with a Part 2 implementation guide.

Subdomain vs Subdirectory

A subdomain (blog.example.com) is a separate hostname; a subdirectory (example.com/blog/) is a path on the same hostname. Google has no blanket ranking preference — it decides per site whether a subdomain is treated as part of the site, based on integration signals.

Related: Website Structure, Canonicalization

Subdomain vs Subdirectory

A subdomain is a prefix added before the root domain, separated by a dot — blog.example.com. Technically it’s a separate hostname, so it can point to a different server, a different CMSA content management system (CMS) is software that lets users create, manage, and publish digital content — like blog posts and pages — without writing raw code. WordPress, Drupal, and Joomla are the most common open-source CMS platforms., or a different team. A subdirectory (or subfolder) is a path segment after the domain, separated by a slash — example.com/blog/. It’s always part of the same hostname, and therefore the same “site” from a crawlingCrawling is how search engines use automated bots (like Googlebot and Bingbot) to discover URLs and download pages. A page has to be crawlable to be indexed, but crawling on its own isn't a ranking factor. and analytics standpoint.

The persistent myth is that subdirectories are SEO-superior. They aren’t, inherently. Google’s official line is that it has no preference, and that you should pick whatever is easiest to organize. The real nuance: Google evaluates per site whether a subdomain is treated as part of the main site or as a separate entity — and the same is true, less often, of subdirectories (Gary Illyes confirmed subdirectories can be treated separately too). The deciding signals are integration: internal linkingAn internal link is a hyperlink from one page on a website to another page on the same website. Internal links help search engines discover your pages and pass ranking signals (PageRank and anchor-text context) between them., consistent branding, and thematically related content.

There are a few concrete functional differences (not ranking myths): subdomains require separate Google Search ConsoleA free Google service that reports how a site performs in Google Search and surfaces problems with how Google crawls, indexes, and serves it. It's first-party data straight from Google — but you don't need it to appear in results. verification; site namesWebSite schema (schema.org/WebSite) is structured data — usually JSON-LD on the homepage — that identifies your domain as a website entity via its name and URL. Today it mainly feeds Google's Site Names feature; the Sitelinks Search Box it used to enable was discontinued by Google in November 2024. in search results work for subdomains but not subdirectories; and Google’s November 2024 site-reputation-abuse policy makes clear that moving content between a subdomain and a subdirectory does not resolve a spam violation. ccTLDsCountry-code top-level domain like .de or .co.uk — a strong geotargeting signal. (example.de) are a third option, used for international targeting and always treated as separate sites.

Related: Website Structure, Canonicalization

Changelog