If we already use a subdomain, is migrating to a subfolder worth it?

Sometimes. We've done several blog.example.com to example.com/blog migrations and seen 20 to 50% organic traffic uplift on the marketing site within four to six months because authority consolidates. The migration is non-trivial, requires careful redirect mapping and carries short-term risk. We recommend it when the subdomain has built meaningful link equity that isn't flowing to the main site. We don't recommend it when the subdomain is small, recently launched or running on infrastructure that can't be re-platformed.

Where should developer documentation live: subdomain or subfolder?

This is the case where subdomains often win. Docs sites usually run on different tooling (Mintlify, Docusaurus, GitBook) than the marketing site, the deployment cadence is different and the audience is different. docs.example.com keeps the engineering and marketing teams operationally separate. The SEO trade-off is real but accepted. For docs that need to rank for educational queries about your product category, a subfolder works better. For pure reference docs serving authenticated users, a subdomain is fine.

Does a subdomain hurt our backlink profile?

Not directly, but it splits where backlinks land. A backlink to blog.example.com/post helps the blog subdomain primarily, with partial flow to the root domain. The same backlink to example.com/blog/post lifts the entire example.com domain. Over time, this means a subdomain strategy needs more total backlinks to produce equivalent ranking outcomes. For tech companies investing in digital PR and content marketing as link-earning activities, that's a meaningful efficiency cost over five years.

Subfolders vs subdomains for tech sites: an SEO take

Subfolders or subdomains. The question comes up in every tech website project where there’s a blog, a docs site, a support hub, a marketing site and possibly a partner portal. The teams running each of those properties have different opinions, the engineering org has constraints and the SEO team usually loses the argument.

This is our take after working through it with a number of B2B tech clients. It’s not a religious view. There are cases for both. The default we recommend is subfolders, but the cases where subdomains make sense are real and worth understanding.

What Google actually says

Google’s public position has been consistent for years: subfolders and subdomains are treated similarly, you can rank well with either, the architecture should match what’s right for the business.

In practice, the SEO community’s experience is that subfolders consolidate authority more reliably. A subdomain is treated by Google as a related but separate site for ranking purposes, even though it inherits some of the parent domain’s signals. The link equity and topical authority earned by your blog flows more directly into the marketing site if the blog lives at example.com/blog than at blog.example.com.

This is generalisation, not law. We’ve seen subdomains rank superbly when the company has invested heavily in them. We’ve seen subfolders fail because the underlying content was poor. Architecture is one factor among many.

The default: subfolders

For most B2B tech companies, our default recommendation is to put the blog, the resources hub, the case studies and any other content marketing on subfolders:

example.com/blog
example.com/resources
example.com/case-studies
example.com/integrations

The reasoning:

Authority compounds in one place. Backlinks earned by the blog improve rankings of the marketing pages and vice versa.
Internal linking flows naturally. No cross-domain linking awkwardness.
The crawl budget on a single domain is more efficient than across multiple subdomains.
Single Search Console property covers everything, single GA4 property, single set of dashboards.
Rebrand or migration is simpler. Our B2B website migration guide covers what changes when domains shift.

If there’s no compelling reason to use a subdomain, use a subfolder.

When subdomains make sense

There are cases where subdomains are the right call. The four we encounter most often:

Documentation that lives in a different platform

Most B2B SaaS companies use a docs platform (Readme, Mintlify, GitBook, Document360) that runs on its own subdomain. Hosting the documentation at example.com/docs is technically possible but often fragile, requiring reverse proxies and edge configuration that breaks under load.

For docs, we generally recommend docs.example.com on the platform of choice. The SEO cost is real but small, and the operational benefit is significant. Engineering teams ship docs faster when the platform is purpose-built. Our developer docs design post covers the wider considerations.

Support hubs and community

The same applies to support knowledge bases (Zendesk, Intercom, Freshdesk) and community forums (Discourse, Vanilla). These run as standalone applications and the path of least resistance is a subdomain. Hosting them as subfolders requires custom integration that the support team probably doesn’t want to maintain.

Support sites also have different SEO targets, often, “[brand] [feature] not working” queries. They don’t need to share authority with the marketing site to rank well, because the queries are heavily branded.

A separate partner portal or app

Login portals, partner portals, app-style interfaces. These should usually be on subdomains (app.example.com, partners.example.com) for security, deployment and user experience reasons. There’s no SEO content here, so the SEO question doesn’t really apply.

Our partner portal subdomain post goes into the structural side of this in detail.

Multi-region or multi-language

For international SaaS, ccTLDs (example.de, example.fr) or subdirectories (example.com/de, example.com/fr) are usually preferred over language subdomains (de.example.com, fr.example.com). But there are cases where regional autonomy and local hosting requirements drive a subdomain decision. Our international SEO for UK-based B2B tech firms post covers this trade-off.

Migrations: subdomain to subfolder

We’ve moved a few clients from subdomains to subfolders. The pattern is consistent.

Pre-migration: blog.example.com has been published independently for years, ranking moderately for a handful of category terms. Marketing site at example.com ranks for branded terms only. The two have grown in parallel without much cross-pollination.

Post-migration to example.com/blog: after the dust settles (typically 4 to 8 weeks), the blog content starts ranking for slightly more competitive terms. The marketing site sees a small lift in non-branded terms because the blog’s authority now flows through. Total organic traffic is up 15 to 30% in the six months after migration.

The migration itself needs care. Our SEO migration guide covers the steps. The points that matter most:

301 redirects for every URL, mapped one-to-one.
Update internal links inside content to the new URLs.
Rebuild the sitemap, submit to Search Console under the new property.
Watch crawl errors and impressions for a few weeks, fix anything broken quickly.

A clean migration recovers within 6 to 12 weeks. A botched one can take 6 months or longer to recover, and some authority is permanently lost.

When subdomains backfire

The pattern that goes wrong most often: a marketing team decides to launch a “resource centre” on resources.example.com because the marketing CMS doesn’t support the layout they want and the engineering team won’t build it. Two years later, the resource centre has 200 pieces of content, ranks for nothing meaningful and gets a fraction of the traffic it should.

The issue is rarely the subdomain in isolation. It’s that nobody linked the resource centre into the main site, the content didn’t earn external links, the topic clusters were fragmented across two domains. Our topic clusters for technology companies post covers what good topical structure looks like, and it’s hard to achieve when content is split across domains without strong interlinking.

Internal linking across the divide

If you do have a subdomain (docs, support, community), make sure it’s internally linked to and from the main site. Practical guidance:

The marketing site should link to relevant docs and support content where it helps the buyer.
The docs and support sites should link back to the marketing site, especially to product pages, case studies and trial signup.
Use HTML anchor links, not just JavaScript navigation that crawlers can’t always follow.
Cross-link case studies to relevant docs and integrations.

This treats the subdomain as part of the site for navigation and authority purposes, even if Google reads it as a related but separate property.

How to decide

A short decision tree we use with clients:

Is the content marketing content (blog, case studies, resources, comparison pages, integrations)? Subfolder.
Is it a technical platform with its own software (docs, support, community, app)? Subdomain, unless you can host it as a subfolder without operational pain.
Is it a different region with different content and possibly hosting? Subdirectory if possible, ccTLD if regional separation matters, subdomain only as a fallback.
Is it a login portal? Subdomain, no SEO concern.

Most decisions resolve quickly with this. The hard cases are content marketing properties (resource hubs, podcast sites) where the marketing team is pushing for a subdomain for platform reasons. Our recommendation is almost always subfolder, with the platform problem solved another way.

If you’re in the middle of this decision and not sure which way to go, tell us about it. Our SEO service page has more on how we approach site architecture and our web design team works through the implementation side.