Topic Clusters: Why (& How) They Help With SEO

It’s no secret that SEO is a constantly evolving field. Google releases search engine algorithms and updates regularly, all with the overall aim of rewarding helpful, people-first content.

Keeping up can be a challenge, however, with each new update and algorithm change comes new opportunities to improve your website’s rankings and search visibility. Like many things in SEO, changes in search can seem enigmatic and mysterious at first.

But fear not, for within the mystery lies strategy.

In the bid to create helpful, people-first content, one such strategy has proven effective time and time again: topic clusters.

In this article, we’ll explore SEO topic clusters and identify how they can be harnessed to boost your website’s rankings.

What are SEO topic clusters?

In SEO, topic clusters are essentially a content marketing strategy that involves grouping related pieces of content (blog posts, articles, etc.) around a central topic or theme. The aim of this is to improve the website’s overall search engine rankings and visibility.

The central pieces of content, usually known as a ‘pillar page’, provide a broader overview of the topic and serve as the main hub that links to the related, more specific, pieces of content known as ‘cluster pages’.

Content cluster

For example, a website on car mechanics might have a pillar page about the engine, then internally link to more specific pieces of content about the different engine parts.

The core idea behind topical clustering is to demonstrate Experience, Expertise, Authoritativeness, and Trustworthiness (E-E-A-T) on a particular subject matter to search engines, which can help increase the chances of ranking higher for relevant keywords.

Why do topic clusters help with SEO?

Topic clusters, also known as content clusters, help improve your site’s SEO in a number of ways. This content strategy helps demonstrate topical relevance, improve authority and trust, focus your keyword strategy, and improve internal linking.

All of which are factors that search engines value. Let’s take a closer look at the many other ways topic clusters help with SEO.

1. Demonstrate topical relevance

Topic clusters make your message to search engines loud and clear; they provide a focused understanding of a particular subject, ensuring that all content within the cluster is highly relevant to its central theme.

This is important for both users and search engines.

By demonstrating topical relevance, your site will attract the right audience and clearly demonstrates the search space you intend to rank in.

2. Improve authority and trust

Content clusters illustrate your expertise and authority on a particular topic, which is important for search engines when determining which websites should appear at the top of the search results.

In fact, Google’s quality rater guidelines explicitly highlight expertise and authority as ranking factors, amongst four key evaluations of content quality:

  • Experience
  • Expertise
  • Authoritativeness
  • Trustworthiness

Or, E-E-A-T for short.

By creating a comprehensive and well-structured cluster, websites can show search engines that they are a trusted source of information on a specific topic.

Think about it, would we trust health advice from a site that only covered the subject broadly on one page? Chances are, we’d be more likely to trust and engage with a site that demonstrates knowledge and expertise in its field.

3. Focus your keyword strategy

Topic clusters allow for better keyword focus. Each pillar and cluster page target a specific set of keywords related to the central theme, which helps the site not only stay relevant to its most important topics, but also rank for a wider range of keywords.

In turn, this can help drive more organic traffic to the website for terms you may not have previously considered.

For example, let’s say a website is focused on fitness and health. By creating clusters of related content around specific topics such as “cardio workouts”, “strength training”, “yoga for beginners”, the website can improve its rankings for a broader range of keywords related to these themes – all of which are relevant to your audience.

4. Improve internal linking

By using internal links to connect pieces of content within each topic cluster, it helps to create a clear and coherent structure throughout the website. This also makes it easier for users and search engines to understand the relationships between different pieces of content.

There are several ways that internal linking with a topical focus can help SEO:

  • Improved user experience: it’s much easier for users to find the content they are looking for when it’s nicely organised and linked together, encouraging a better overall user experience.
  • Increased page views: when people are able to find the information they need quickly and easily, they’re more likely to spend more time on the website and explore related content. This can in turn help encourage additional page views.
  • Better crawlability: search engines love websites with clear, organised structures. It makes it easier for search crawlers to understand how the site is divided, and the hierarchy of different pages. By using topic clustering and internal linking, you’ll help make the relationship between pages clear, improving the site’s crawlability.

5. Match search intents

Topic clusters provide a comprehensive and holistic approach to content creation that addresses a user’s search query from multiple angles. By doing so, topic clusters can ensure that the user can find the relevant content that matches their search intent. This is especially useful when focusing on long-tail keywords, where users are looking for very specific information on a particular topic.

Let’s say you’re creating a topic cluster on “hiking in the Peak District.” The user intent behind this search query could be to find a list of the best hiking trails, to get more information on a specific trail, or simply to learn more about hiking in the Peak District.

To match these different search intents, you might create a topic cluster that includes:

  • A pillar page that provides an overview of hiking in the Peak District, introducing popular hiking trails and routes.
  • Cluster pages providing more specific details on each of the popular hiking trails. This might include maps, difficulty ratings and trail attractions. These cluster pages would serve the intent of users who are looking for more details on specific trails.

Additional cluster pages that cover related topics. For example, “what to pack for a hiking trip in the Peak District” or “best places to stay near the Peak District.” These subtopics would match the intent of users who are looking for more information on hiking in the Peak District beyond just the trails themselves.

How do topic clusters work? The role of semantics

On the surface, topic clusters seem like a concept that just makes sense.

When you think about it, we have a natural intuition to categorise and organise information, helping us make sense of the world around us. It’s why you’ll walk into any library and find sections dedicated to specific topics, why cities are divided into neighbourhoods, and why your wardrobe is (hopefully) sorted by clothing type.

But, like most things in life that ‘just make sense’, there’s actually a logical reason behind it. In the case of topic clusters, it’s semantics.

Semantics is the study of meaning in language, and is concerned with how words, phrases, and sentences are used to convey meaning. Most importantly, semantics explores the relationships between words, their meanings, and the concepts they represent.

For example, semantics helps us understand why we know that horses and donkeys are similar, and that the words ‘play’ and ‘playful’ are related. 

Interestingly, search engines also understand language in this way. In order to interpret language semantically, Google uses Natural Language Processing (NLP) to understand language in similar ways to humans. In turn, this allows for an understanding of how different concepts on the web are connected

Topic clusters are embedded in Google’s semantic NLP abilities.As a result, linguistic considerations in SEO have become increasingly important in recent years; particularly in the context of semantic SEO.

How to create SEO topic clusters

Creating topic clusters requires planning, research and organisation. Through a streamlined pillar-topic cluster model, you can start delivering better content in a way that makes sense to your target audience. 

In this section, we’ll talk you through how to create topic clusters step by step.

Step 1: Identify your core topic

Start by choosing a broad topic that you want to focus on and create a piece of in-depth content for. This will be your “pillar piece” that the cluster content pieces form around. Your pillar piece should be a strong, comprehensive article that provides a thorough overview of the topic.

Coming up with content ideas can be difficult, but try not to overthink it. Essentially, your pillar topic should be one that your audience will value. For example, if your business provides home electric car chargers, you could consider a guide that covers the need for home chargers and the options available.

One way to uncover potential topics is to use a keyword research tool. This will help you identify relevant terms that people are searching for, and the kind of search demand behind each area. For pillar content, you’ll want to go with more generic terms – the cluster content is where you can go more specific.

You can think of the pillar like the trunk of a tree, and the subtopics its branches. The trunk provides stability, and the branches offer finer details. But just as a tree with a weak trunk will eventually fall, so too will pillar content that isn’t sturdy.

So, spend time deciding on a pillar topic that provides value to your audience – your entire topic cluster relies on it!

Step 2: Research subtopics

Once you’ve decided on your core topic, identify subtopics that relate to the main pillar piece. You can find relevant subtopics using a range of research methods, including Search Engine Result Page (SERP) feature analysis, and keyword research tools.

Analysing SERP features

SERP feature examples

SERP features are the additional elements displayed on a search results page beyond the traditional organic listings. These features are intended to enhance the user experience by providing more relevant information upfront, and they also represent the subtopics that Google understands as relevant to the provided search query.

Here is a list of SERP features you can use to uncover subtopics:

  • People also ask: an interactive box that includes related questions that users commonly ask.
  • Related searches: a section at the bottom of the search results page that displays additional search queries related to the original query.
  • Google autocomplete: a dropdown list of related search queries that appears as the user types their query into the search bar.

Knowledge graph: a box on the right side of the search results page that provides additional information about the search query, including related topics.

Topical keyword research tools

There are a range of keyword research tools that focus specifically on identifying topically relevant search terms. Two of the most popular tools include:

  • Answer The Public: generates a list of Google autocomplete data related to the keyword you provide.
  • Also Asked: generates live ‘people also ask’ data related to your keyword.

Step 3: Outline a pillar and content cluster structure

Content clustering is all about organisation. Make sure to organise your topic cluster strategy from the start.

The best way to stay on track is by going one step at a time. Fill out a content calendar in a tool of your choice, such as Google Sheets. Add your target keywords, organising them by topic. You can then sort them by priority, making it much easier to focus on the most relevant terms first. 

Organising your topic clusters in Google Sheets is also a great way to link all of your content documents in one place, where you can easily make changes, track progress, and share content with others in the team.

Step 4: Create cluster content

Cluster content should delve deeper into specific aspects of the main subject. Once you’ve identified and organised the specific areas that relate to your main topic, it’s time to write about these in more detail.Produce individual pieces of content for each subtopic, ensuring that each page focuses on a specific, unique aspect of the main topic. When writing long-form SEO content, make sure to use headings, images and clear sentence structure to make the content engaging and easy to read.

When you’re happy with your pillar and cluster content, publish it to your site! This will be an ongoing process as you develop your content. 

But, the work doesn’t stop there. Make sure to link each cluster page back to the main pillar piece once it’s been published. This will help show search engines (and users!) how the pages are related, and ultimately form your topic cluster.

Don’t forget to also interlink subtopic pages. Link these together where relevant to demonstrate the relationships between different pages in the cluster.

Clustering existing content: from chaos to clarity

If you already have a lot of existing content on your website, not to worry, you can still create topic clusters by grouping related content into subtopics.

Here are some steps you can take to create topic clusters using existing content.

Step 1: Export your site’s URLs

Start by exporting your site’s URLs, which you can do with a range of tools such as Screaming Frog’s SEO Spider, or directly from your Google Analytics property. Once exported, take a look at what content you already have, and where there may be opportunities to group pages into topic clusters.

Organise pages into meaningful categories. This will help you identify potential topic clusters.

Step 2: Identify existing pillar content

From your list of existing content, take a look at the main topics and identify the pieces that you consider the broadest and most relevant to your brand.

These pieces will form the pillar content for your topic clusters.

Take a website that sells electric car chargers, for example. One pillar piece could be an electric car charging guide that covers general tips and considerations for fresh electric vehicle buyers.

If pillar pages don’t exist, make a note of where you plan to add these to the site.

Next, identify the content that would serve as relevant subtopics that support the main pillar piece. Make a note of how these existing pages will group together with the pillar page.

Tip: you can use your exported URLs to group pages together in a spreadsheet!

These more granular pages will form the cluster content.

For example, cluster content that could support the electric car charging guide would likely cover the costs, charging times, charger types, and other specific details related to electric car charging.

Don’t forget the final touch – link your cluster content pieces to and from the main pillar piece! Keep track of your progress using the exported URL list.

Additionally, interconnect clusters by linking their pages to one another wherever relevant.

This will help your topic clusters deliver a seamless user experience and search engines understand the relationships between each piece.

The bottom line

SEO trends come and go, but topic clustering is a strategy that’s here to stay.

Google’s improved natural language processing (NLP) abilities, particularly in semantics, have made it even more important to organise your content meaningfully using topic clusters.

This approach not only improves your chances of ranking higher in search results, but also helps you create a more user-friendly experience for your users. 

In short, topic clustering is a powerful strategy that takes advantage of Google’s impressive language processing capabilities, and it’s likely to remain an essential component of SEO for years to come.