Subdomain vs. Subfolder: The Definitive SEO Guide for Landing Pages

Choosing whether to host landing pages and other content on a subdomain (e.g., go.site.com) or a subfolder (e.g., site.com/go) is a critical architectural decision with significant SEO implications. While search engines state they are adept at understanding both structures, the long-standing consensus in the SEO community is that subfolders are generally superior for consolidating authority and maximizing SEO performance. This is because content and backlinks to a subfolder contribute directly to the main domain's strength. However, subdomains are often a technical necessity, especially when using third-party platforms for landing pages, blogs, or distinct international content. Understanding the trade-offs is key to making an informed decision that aligns with your technical capabilities and strategic goals.

We use a subdomain like 'go.ourcompany.com' for our marketing landing pages. What are the SEO implications?

Using a subdomain like go.ourcompany.com for marketing landing pages means that search engines, such as Google, will likely treat it as a website separate from your main domain. The primary implication is that the SEO authority, determined by factors like backlinks and high-quality content, is fragmented. Backlinks earned by your main site may not benefit the subdomain, and conversely, any authority your landing pages build will primarily strengthen the subdomain, not the main site. This setup is common for pages built on third-party platforms like HubSpot, which often default to subdomains. It requires a dedicated SEO strategy, including link building, to establish the subdomain's authority as if it were a new site.

What is the difference between a subdomain (go.site.com) and a subfolder (site.com/go)?

The difference lies in their position within the URL and how they structure a website.

• A subfolder (also called a subdirectory) is a path within your main website, like a folder on a computer. For the URL site.com/go, 'go' is a subfolder of site.com. It is part of the same website entity.
• A subdomain is a prefix added to your main domain, creating what search engines often treat as a new, separate website. For the URL go.site.com, 'go' is the subdomain. It functions as a distinct site that is still related to the main domain.

Does content on a subdomain contribute to the main domain's authority?

Generally, content and backlinks on a subdomain do not directly contribute to the main domain's authority. Search engines tend to view subdomains as separate entities, meaning each one must build its own backlink profile and authority from the ground up. While Google has indicated its systems are improving at associating subdomains with a primary domain, the established and safer SEO practice is to assume they are separate. Any authority built on a subdomain, such as from a successful blog, may not be transferred to the root domain. Strategic linking between the two can help pass some value, but it doesn't consolidate authority in the same way a subfolder does.

If we use a platform like Webflow or HubSpot for landing pages, will they be on a subdomain?

Yes, typically platforms like HubSpot and Webflow host landing pages, blogs, and other content on a subdomain by default (e.g., go.yourcompany.com). This is the standard technical method for pointing your domain to an external hosting service. While some platforms may offer a subfolder structure through a complex setup called a reverse proxy, it is often limited to enterprise-level plans and is not a standard feature. For most users, the subdomain is the practical and intended implementation.

Are there any risks if we use the same subdomain for pages built on different platforms?

Using the same subdomain for pages built on different platforms is not technically feasible. A single subdomain, such as go.site.com, can only point to one hosting location or server via its DNS records (e.g., a CNAME record). You cannot have one page on that subdomain hosted by HubSpot and another page on the same subdomain hosted by Webflow. To use multiple platforms, you would need to configure separate, unique subdomains for each one (e.g., hub.site.com and web.site.com).

From a tracking perspective, is it harder to track user journeys across a main domain and a subdomain?

Yes, tracking user journeys across a main domain and a subdomain is more complex than tracking within a single domain. Standard analytics configurations will treat a user moving from site.com to go.site.com as two separate sessions from two different users, with the main site appearing as a referral source to the subdomain. To get a unified view of a single user's journey, you must implement what is known as cross-domain tracking in your analytics tool, such as Google Analytics 4. This ensures that user sessions are stitched together seamlessly across the different properties.

Which structure is generally better for SEO: subdomains or subfolders?

For SEO purposes, the overwhelming consensus is that subfolders are better. A subfolder structure (site.com/content) consolidates all content and backlinks under a single root domain. This means that every piece of content contributes to the site's overall authority, making it easier to rank. While Google has officially stated it treats them similarly, case studies and expert opinions have repeatedly shown that moving content from a subdomain to a subfolder can improve rankings.

If we have to use a subdomain, what can we do to maximize its SEO value?

If a subdomain is necessary, treat it as a distinct website with its own dedicated SEO strategy. Key actions include:

• Build Authority: Develop a dedicated link-building strategy to acquire high-quality backlinks directly to the subdomain's content.
• Create Unique Content: Ensure the content on the subdomain is unique and valuable, not duplicated from the main site, to avoid penalties.
• Perform Technical SEO: Each subdomain needs its own robots.txt file and a unique XML sitemap submitted to Google Search Console to ensure proper crawling and indexing.
• Link Strategically: Create relevant links from your main domain to the subdomain (and back) to pass some authority and signal to search engines that the sites are related.

How does Google view content on a subdomain? As part of the main site or a separate entity?

Google generally views a subdomain as a separate entity from the main root domain. While Google's John Mueller has stated that their algorithms have improved at understanding the relationship between them, it is not a guarantee. For strategic planning, it is safest to assume that a subdomain starts with little to no inherited authority from the parent domain and must establish its own credibility and ranking power through its own content and backlink profile.

Can having too many subdomains dilute our brand's authority?

Yes, creating numerous subdomains can dilute your overall SEO authority and fragment your brand identity. Instead of concentrating all your content and backlinks to strengthen a single, authoritative domain, you are spreading your efforts across multiple, weaker properties. Each subdomain essentially starts from scratch and competes for authority, which can make it harder to rank for competitive terms compared to a consolidated approach using subfolders.