When you want to build a new section of your website, the question often arises: should the content be located under a subdomain or in a subdirectory?
Both variants are technically possible and can be indexed by search engines. The decision should therefore not be based on the blanket assumption that a subdomain or a subdirectory inherently ranks better on Google.
More important are the technical architecture of your website, the topical relevance, internal linking, user navigation, and the question of whether a section should be operated intentionally independently.
Briefly explained: A subdirectory like
example.ch/blog/is an area within the same website or the same hostname. A subdomain likeblog.example.chis a separate hostname instead. For SEO, there is no simple rule of „subdirectory good, subdomain bad“.
What is a subdirectory? #
A subdirectory is located within the URL structure of an existing website.
Examples:
https://example.ch/blog/
https://example.ch/hilfe/
https://example.ch/shop/The main domain or hostname remains the same:
example.ch
Only the path behind the domain name changes.
At CURIAWEB, for example, the knowledge base is also structured according to this principle:
The knowledge base is therefore part of the existing website and not a separate hostname.
What is a subdomain? #
A subdomain precedes the actual domain name.
Examples:
blog.example.ch
shop.example.ch
support.example.ch
my.example.chTechnically, a subdomain is a separate hostname and can point to a different infrastructure independently of the main website.
For example, can
example.ch
shop.example.chbe operated on different servers.
What is the technical difference? #
For a subdirectory, the hostname remains the same:
example.ch/blog/
example.ch/shop/
example.ch/hilfe/By contrast, a subdomain creates an additional hostname:
blog.example.ch
shop.example.ch
hilfe.example.chThis difference has technical consequences. For example, a subdomain may require its own DNS records, its own hosting configuration, and its own SSL/TLS certificate or corresponding certificate coverage.
We explain what role DNS records play in this at DNS Records Explained: A, AAAA, CNAME, MX, TXT, and CAA.
Is a subdomain a separate domain? #
No.
At
blog.example.ch
is example.ch still the registered domain. blog is a subdomain or hostname set up underneath it.
You therefore normally do not have to register a new domain for every subdomain.
We explain the differences between domain and URL at Website, Domain, and URL: What is the difference?.
Is a subdirectory better for SEO? #
Not fundamentally.
However, subdirectories have an important structural advantage: content that is clearly part of the same website can be organized very easily within a shared URL structure.
For example, a corporate blog could be found at
example.ch/blog/
lie and the knowledge base under
example.ch/help/.
This makes it immediately recognizable to users that this content belongs to the main website.
However, this alone does not guarantee better rankings. Content quality, search intent, internal linking, crawlability, technical quality, and many other factors remain decisive.
Important: A subdirectory does not automatically get good rankings just because the main domain is already established. Content in a subdirectory must also be relevant, crawlable, and of convincing quality.
Is a subdomain bad for SEO? #
No.
Subdomains can be crawled and indexed by search engines and can also achieve good rankings.
Therefore, a subdomain is not automatically an SEO mistake.
Rather, what is crucial is whether the chosen structure makes sense for the respective website area and is implemented cleanly from a technical standpoint.
Does Google treat a subdomain as a separate website? #
A blanket statement like „Google treats every subdomain completely like a foreign website“ is too simplistic.
Technically, a subdomain is a separate hostname. Google also differentiates between domains, subdomains, and directories in various functions and systems.
However, that does not automatically mean it results in a blanket SEO disadvantage.
Note: „Custom hostname“ and „worse rankings“ are two completely different statements. No automatic ranking disadvantage can be derived from the technical independence of a subdomain.
When is a subdirectory useful? #
A subdirectory is often a good choice when the new section clearly belongs to the existing website.
Typical examples are:
example.ch/blog/
example.ch/guide/
example.ch/help/
example.ch/references/
example.ch/products/The content can be integrated into a common navigation, internal linking, and information architecture.
Therefore, a subdirectory is often a very natural solution for a corporate blog or a knowledge base.
When does a subdomain make sense? #
A subdomain can be useful if a section is to be technically or functionally clearly separated from the main website.
Examples can be:
my.example.ch
app.example.ch
status.example.ch
dev.example.chFor example, a customer portal, a web application, or a status system may use completely different software and infrastructure than the public corporate website.
In such cases, technical separation can be more important than the desire to operate all content under a common directory path.
Can a subdomain be hosted on a different server? #
Yes.
This is one of the major technical advantages of subdomains.
For example, the main domain can point to a web server:
example.ch
while
app.example.ch
points to a different infrastructure via its own DNS record.
This enables a clean separation of different applications and systems.
Can a subdirectory be on another server? #
Technically this is also possible, but usually more complex.
Since
example.ch/app/
the same hostname is used as for the main website, the separation is not simply done via a separate DNS entry for the directory.
Instead, corresponding reverse proxy, web server or application rules would be required, for example.
DNS works with hostnames and not with URL paths like /app/.
Briefly explained: DNS can
app.example.chtax separately, but not directlyexample.ch/app/. The path only becomes relevant after connecting to the web server.
What is better for a blog? #
If the blog is a normal part of the company website, a subdirectory is often the simpler and more logical structure:
example.ch/blog/
This allows the blog to be integrated directly into the navigation, internal linking, and the rest of the website structure.
A subdomain like
blog.example.ch
can still make sense if there are technical or organizational reasons for a separation.
Solely for SEO reasons, an existing, functioning blog structure should not be reorganized without a concrete necessity.
What is better for a knowledge base? #
Here too, the decision depends on the technical and organizational structure.
If the knowledge base is part of the main website, it is a good idea, for example:
example.ch/help/
If, on the other hand, a completely standalone support system or an external application is used, a structure like
support.example.ch
be more technically sound.
The crucial factor is not the claim that one variant is fundamentally stronger for SEO, but rather which architecture for content and system makes sense in the long term.
What is better for an online shop? #
If the shop and main website are closely linked and use the same content management system, a subdirectory can make sense:
example.ch/shop/
On the other hand, a technically completely separate shop system could under
shop.example.ch
be operated.
Here too, the decision should be made based on technical requirements, maintainability, user guidance, and the long-term URL structure.
What is better for a customer area? #
For a customer area, a subdomain is often a very sensible solution.
For example:
my.example.ch
This allows the customer area to be operated technically independently of the public website.
This is especially practical when different applications are used.
Furthermore, a customer portal does not necessarily have to meet the same SEO requirements as publicly indexable informational or product pages.
What about internal links? #
Regardless of the chosen structure, the internal linking should be set up sensibly.
A blog, guide, or help section should not exist in isolation if its content is relevant to visitors of the main website.
Link thematically related content wherever the link actually helps the user.
Clear navigation and information architecture are more important than trying to generate rankings through a specific URL structure alone.
What happens to backlinks? #
Backlinks point to specific URLs.
An external link to
is therefore not the same link as one on
When existing content is moved from one structure to another, the URLs change, and the old addresses should be redirected to the new destinations accordingly.
Should I switch from a subdomain to a subdirectory for SEO reasons? #
Not solely based on the blanket statement that subdirectories are always better.
A change of
blog.example.ch
to
example.ch/blog/
changes the URLs of the entire section.
This results in a website migration. Existing URLs must be redirected to their new destinations, and internal links, canonical tags, sitemaps, and other technical signals must be updated accordingly.
Therefore, a functioning and established structure should not be migrated without a specific technical, organizational, or strategic reason.
Attention: A URL migration solely due to a perceived „subdomain SEO disadvantage“ can create more effort and risk than it brings benefits.
What do I need to consider during a migration? #
When content is moved from a subdomain to a subdirectory or in the reverse direction, a suitable new destination should be defined for each relevant old URL.
For example:
blog.example.ch/artikel-a/
↓
example.ch/blog/artikel-a/
blog.example.ch/artikel-b/
↓
example.ch/blog/artikel-b/For permanently moved content, appropriate permanent server-side redirects should be used.
Internal links, XML sitemaps, and canonical tags must also match the new structure.
What about duplicate content? #
It can become problematic if identical or nearly identical content remains accessible under multiple URLs at the same time.
For example:
blog.example.ch/ratgeber/
example.ch/blog/ratgeber/If both versions permanently serve the same content, it must be clear to search engines which URL is the preferred or canonical version.
In a real migration, it is usually cleaner to permanently redirect the old URL to the new URL instead of running both structures in parallel indefinitely with identical content.
Can I publish the same content on a subdomain and a subdirectory? #
Technically that is possible, but usually not sensible for the same purpose.
Several identical URLs do not automatically improve content. Instead, they can create unnecessary duplicates and complicate website analysis.
If there is no objective reason for multiple versions, content should have a clear primary URL.
How does Google handle canonical URLs? #
When Google finds multiple identical or very similar pages, it evaluates them together for canonicalization.
Website operators can, for example, with redirects, rel="canonical" and provide hints regarding the preferred URL through consistent sitemap data.
However, Google may ultimately choose a different URL as canonical if the existing signals suggest it.
A clean and consistent URL structure is therefore better than contradictory signals between multiple versions of the same page.
Does a subdomain need its own DNS records? #
A subdomain must be able to be resolved accordingly via DNS.
For this, an A, AAAA, or CNAME record can be used, for example.
Which variant is correct depends on the desired target infrastructure.
With the CURIAWEB DNS-Check Can you check publicly visible DNS information?.
Does a subdirectory need its own DNS record? #
No.
A URL path like
example.ch/blog/
is not controlled via a dedicated DNS record.
DNS resolves the hostname example.ch auf. Welcher Inhalt anschließend unter /blog/ ausgeliefert wird, entscheidet der Webserver beziehungsweise die darauf laufende Anwendung.
Braucht eine Subdomain ein SSL-Zertifikat? #
Wenn die Subdomain über HTTPS erreichbar sein soll, muss sie von einem gültigen SSL-/TLS-Zertifikat abgedeckt sein.
Ein Zertifikat, das nur für
example.ch
gültig ist, deckt nicht automatisch
blog.example.ch
ab.
Je nach Zertifikat können mehrere Hostnamen oder Subdomains enthalten sein. Auch Wildcard-Zertifikate können für bestimmte Subdomain-Konstellationen eingesetzt werden.
Kann eine Subdomain eine eigene Search-Console-Property haben? #
Ja. Abhängig vom verwendeten Property-Typ können Subdomains beziehungsweise URL-Präfixe in der Google Search Console separat betrachtet werden.
Das kann bei größeren technisch getrennten Bereichen hilfreich sein.
Eine Domain-Property kann dagegen Daten über verschiedene Protokolle und Subdomains einer verifizierten Domain zusammenfassen.
Kann Google Subdomains und Unterverzeichnisse unterschiedlich behandeln? #
Ja, in bestimmten Google-Funktionen gibt es technische Unterschiede zwischen Hostnamen und Verzeichnissen.
Beispielsweise definiert Google für einige Suchfunktionen eine Website auf Hostname-Ebene. Eine Subdomain kann dort deshalb separat behandelt werden, während ein Unterverzeichnis Bestandteil des bestehenden Hostnamens bleibt.
Das sollte jedoch nicht mit einer allgemeinen Aussage über Rankings verwechselt werden.
Important: Technische Unterschiede bei Hostnames, Search-Features oder Properties sind kein Beweis dafür, dass Google Inhalte auf Subdomains grundsätzlich schlechter rankt.
Welche Variante ist einfacher zu verwalten? #
Wenn sämtliche Inhalte mit derselben Website beziehungsweise demselben CMS betrieben werden, ist ein Unterverzeichnis häufig einfacher.
Es benötigt keine separate DNS-Zuordnung für den jeweiligen Bereich und lässt sich meist unmittelbar in Navigation und URL-Struktur integrieren.
Wenn unterschiedliche Anwendungen, Server oder Teams beteiligt sind, kann eine Subdomain dagegen eine sauberere technische Trennung ermöglichen.
Welche Variante würden wir für normale Website-Inhalte wählen? #
Für Inhalte, die eindeutig Teil derselben Website sind – beispielsweise Blog, Ratgeber, Knowledgebase oder Leistungsinformationen – ist ein Unterverzeichnis häufig eine logische und wartungsfreundliche Lösung.
Für technisch eigenständige Systeme wie Kundenportale, Webanwendungen, Entwicklungsumgebungen oder Statusseiten kann dagegen eine Subdomain sinnvoller sein.
Das ist eine Architekturentscheidung und keine pauschale SEO-Regel.
Welche Fragen sollte ich vor der Entscheidung beantworten? #
Statt nur zu fragen „Was ist besser für SEO?“ solltest du prüfen, welche Rolle der neue Bereich tatsächlich erfüllt.
Gehört der Inhalt fachlich und organisatorisch zur Hauptwebsite? Wird dasselbe CMS verwendet? Soll der Bereich dieselbe Navigation und Nutzerführung verwenden? Oder handelt es sich um eine technisch eigenständige Anwendung, die unabhängig betrieben werden soll?
Je stärker ein Bereich mit der Hauptwebsite verbunden ist, desto natürlicher kann ein Unterverzeichnis sein. Je stärker die technische Eigenständigkeit im Vordergrund steht, desto sinnvoller kann eine Subdomain werden.
Summary #
Subdomains und Unterverzeichnisse sind zwei unterschiedliche Möglichkeiten, Inhalte und Dienste unter einer Domain zu strukturieren.
A subdirectory like example.ch/blog/ bleibt Bestandteil desselben Hostnamens. Eine Subdomain wie blog.example.ch ist dagegen ein eigener Hostname und kann technisch unabhängig auf einer anderen Infrastruktur betrieben werden.
Für SEO gibt es keine seriöse allgemeine Regel, nach der ein Unterverzeichnis automatisch besser rankt oder eine Subdomain grundsätzlich schlechter wäre.
Für eng mit der Hauptwebsite verbundene Inhalte wie Blog, Ratgeber oder Knowledgebase ist ein Unterverzeichnis häufig eine einfache und logische Struktur. Für technisch eigenständige Anwendungen wie Kundenportale oder separate Systeme kann eine Subdomain die bessere Architektur darstellen.
Wenn bereits eine funktionierende Struktur existiert, sollte sie nicht allein aufgrund vermeintlicher SEO-Vorteile geändert werden. Ein Wechsel zwischen Subdomain und Unterverzeichnis verändert URLs und muss als Migration mit korrekten Weiterleitungen und weiteren technischen Anpassungen behandelt werden.
Wähle die Struktur deshalb nach Inhalt, Technik und langfristiger Wartbarkeit – nicht aufgrund des Mythos, dass Google eine der beiden Varianten grundsätzlich bevorzugt.
