Digital estates with many subdomains are complex for users to navigate and expensive for organisations to maintain. We examine when to fold subdomains back into your main site, and how to do it right.
Introduction
Digital estates have a habit of growing over time. Both in terms of the number of pages on your website, but also the number of separate websites or subdomains you manage. Projects with separate subdomains might be spun up for a whole host of reasons – serving a new audience, a one-off campaign, or a new sub-brand.
For large organisations, particularly in higher education, this can mean your digital estate grows to be unmanageably large. One approach to regain control and reduce costs is to bring all your separate subdomains together into a single, unified website. In this article we’ll investigate the pros and cons of unifying or keeping them separate, so you can make the right decision for your organisation and your users.
Why use separate subdomains?
Separate subdomains aren't inherently problematic. When used strategically, they can be powerful tools for achieving specific goals. For example:
Focused campaign experiences
Campaign microsites excel at one thing – removing distractions. Without the weight of your main site's navigation, footer links and competing content, visitors can focus entirely on your campaign’s message. The Children's Society demonstrated this beautifully with a campaign landing page that featured interactive quizzes and focused storytelling. The result? Higher engagement and clearer conversion paths.
Distinct audience needs
Sometimes your audiences are so different they need completely different experiences. Take Crick Kids – a science education programme by the Francis Crick Institute. Their young audience needed vibrant, playful design and simplified navigation that would have felt out of place on the main institution’s website.
Another clear example of a totally distinct audience with separate needs is the booking of accommodation in university halls outside of term time. Many universities rent out their student accommodation in summer to non-student visitors. This has so little overlap with the needs of most users of a university website, that it makes sense to maintain it as a separate subdomain that’s not part of the main site.
The disadvantages of separate subdomains
Launching a new subdomain can be tempting when you’ve got an exciting new idea you’d like to bring to life online. But over time, these can mean a disjointed digital presence that’s more expensive to maintain and less useful for your users. We think you should have a high threshold to justify the creation of a separate subdomain, and more often than not, the right approach is a new section of your existing site that's thoughtfully added to your site’s information architecture. Here's why we’d usually advise against adding separate subdomains:
SEO and discoverability challenges
If you maintain separate sites, then instead of strengthening your domain authority with one powerful domain, you're diluting your efforts across multiple weaker ones. Search engines are increasingly ranking content by assessing all your content across a given topic cluster, to establish if your organisation is an expert in that subject. If these are split across separate sites, your content will be less likely to rank.
Confusing user journeys
Subdomains prevent users exploring your digital offering more widely, by keeping them ‘bottled up’ in a single area. This can be frustrating for users if they end up on a subdomain that makes it difficult to navigate back to your main site. For clearer journeys and breadcrumb structures it’s usually better to maintain all your content on a single site.
Complex content governance
Who's updating that campaign site from three years ago? Is the tone of voice consistent across all your domains? Are accessibility standards being maintained? The more separate sites you maintain, the harder it becomes to answer these questions. Standards slip, outdated information lingers, and your brand voice fragments across different platforms.
Costs multiply
Each site needs hosting, security updates, and maintenance. Design updates must be rolled out multiple times. Training happens in silos. These costs – both financial and temporal – compound quickly, draining resources that could improve your user experience. If your sites use different content management systems, the problem is even worse. You might have to maintain developers with different skill sets, meaning far greater overheads than using a single system.
How to know when to unify
Digital estates grow over time, so older organisations often have digital estates that have become too large and complex. It may be time to draw a line in the sand, and start unifying your digital estate by folding separate subdomains back into a single site.
It’s tough to know when to unify, but these questions should help you get to the right answer:
Is there genuine user need for the content? If the content isn’t serving your users’ needs, then you shouldn’t be wasting resources on it. Consider shutting the subdomain and only migrating any content that’s working. A thorough content audit should show you what isn’t getting used, and therefore what shouldn’t be migrated.
Does the content fit logically within your current site? Look at your information architecture. Is there a natural home for this content that users would expect? If yes, it should live there, and not on a separate site.
Do you have similar content already? If you're already covering related topics, integration usually makes more sense than separation.
Is this evergreen content or time-limited? Permanent content deserves proper integration on your main site. Temporary campaigns might justify separate treatment.
Are the user groups genuinely distinct? Different audiences aren't enough. Their needs must be completely unrelated to your main site’s focus. Don’t make too many assumptions about user behaviour, the world is messier than your neatly distinct customer personas imply. It’s usually best to assume some overlap unless your user research is crystal clear that there is none.
Is significant brand differentiation essential? Not just nice-to-have – is it genuinely needed for the content to achieve its goals? If not, it’s best to avoid the increased costs and design overhead of maintaining separate sites.
How to unify successfully
If you’ve decided to consolidate your digital estate by folding subdomains back into your main site, then we can help. We’ve helped big institutions like the University of London get to grips with sprawling digital estates, and reduce 10 separate websites down to just the main site and a single subdomain. These are big, complex projects so you’ll likely want to find the right partner to help you through the process. But we can give you some pointers for getting started:
Revisit your information architecture
Unification isn't just moving content – it's rethinking how everything fits together. This is your chance to create logical, user-centred structures that make sense across all your content.
Map out where content naturally belongs. Look for overlaps and redundancies. Most importantly, think from your users' perspective, not your organisational chart.
For guidance on creating an effective information architecture, centred on user need, read our article on topic and audience based information architectures.
Audit ruthlessly
Unification provides the perfect opportunity for a content cull. It may sound harsh, but pages like old news sections from subdomains that haven’t been updated in years are costing you hosting while providing no benefit to your users. They are best off being shuttered, rather than wasting time and money migrating them.
Plan your redirects carefully
Every URL on your old sites needs a new home or a graceful goodbye. Map redirects thoughtfully to maintain SEO value and ensure users following old links find relevant content.
Invest in a modular, flexible design system
One reason organisations create separate sites is because their main platform feels too rigid for creative content. Modular, flexible design systems solve this. At Numiko, we build flexible systems that allow content admins to easily create effective new pages for new campaigns or use cases with their existing CMS. When your main site can handle diverse content needs, the temptation for microsites disappears.
Making the right choice for your organisation
There’s no one-size-fits-all approach to running effective digital estates, but in our experience, unification is usually the right ‘default’ choice. You need compelling reasons to justify separation, given its tendency to add cost and complexity. But when those reasons exist – truly distinct audiences, fundamental brand differences, focused campaign needs – separation can be the right approach.
The key is making these decisions strategically, not accidentally. Your digital estate should grow through intention, not neglect. Every domain should earn its place through clear user benefit, not organisational convenience. If you’re wrestling with these questions, start by reviewing your analytics. Which sites drive real engagement? Which gather digital dust? The answers might surprise you – and point the way toward a more focused, effective digital presence.
Consolidating a big digital estate is a major project, so it helps to have an experienced team on hand who’ve seen it all before. We can help with an effective content strategy, assist with business-case creation, and deliver a flexible and high performing website.
