What are keyword clusters and how to build them
Marketing Intelligence

Keyword Clusters – A Guide to Pumping Up Your Ranking

by Ruth Trucks , Senior Marketing Writer 7 Min.
July 8, 2022 | Updated September 12, 2022

Google’s priorities are shifting from keywords to search intent, and SEO strategies need to follow suit. It’s no longer sufficient to target one or two keywords per page. Google wants to satisfy the searcher’s intent, and keyword clustering is a way to help the search engine get it right.

We’ll explain what keyword clustering is, and how you and your audience benefit from it. You’ll learn what to do and also what not to do when applying the concept.

Read on to get tips so you can start clustering.

Keyword Clusters lead to pages ranking for 20x more keywords

What is keyword clustering?

In a nutshell, keyword clusters are groups of keywords that target the same search intent. Creating keyword groups is called keyword clustering. It is the process of combining related, similar search terms into semantically aligned batches and targeting them as a whole rather than independently.

A cluster is made up of a core keyword and related keywords grouped around it. The structure allows you to target multiple search terms in the same piece of content. At the same time, you develop an interlinked body of content for your business-related topics based on the keyword cluster.

How is keyword clustering different from topic clustering?

Keyword clustering refers to the process of organizing relevant keywords in a cluster form. As a result, the content on your site gets structured accordingly. Keyword clusters are the foundation for your search-optimized topic clusters.

How to build keyword clusters

1. Collect relevant keywords. There are various methods, and we recommend combining them.

  • Brainstorm ideas and play around with variations and combinations of words. Find synonyms and alternative expressions.
  • Use the keyword generator in a keyword tool to find additional related keywords. Enter the keywords you’ve collected to find search terms with similar meanings
  • Research keywords targeted by your competitors. Use the Similarweb keyword gap tool to identify which keywords drive traffic to your competitors but not to your site.

Screenshot of Similarweb Keyword Gap results.

The Similarweb keyword gap tool provides you with relevant data about the keywords you are missing.


2. Organize the terms including relevant search data in a spreadsheet. Add metrics that help evaluate and prioritize, such as keyword difficulty, search volume, zero-click rate, and CPC.

You can find hundreds, if not thousands of keywords. Moz estimates they identify 1,000 – 6,000 search terms to target per website. If you’re just getting started, you don’t need that many, but don’t leave anything out at this stage.

3. Identify the core keywords that represent a topic or category. These will build the pillars around which to create the cluster. It is important that these are highly relevant for your business. They need to match search intent and have high economic value.
There’s a purely mathematical way to uncover the words that appear most often in your list. Google Sheets has a frequency counter to automate the process.

However, for beginners with a shorter list, it’s enough to manually identify the most popular and relevant keywords from your pillars.

4. Segment keywords into groups. By now, you’ll detect patterns in the search terms like recurring word combinations. Your guide for segmentation should be semantic relevance. Semantically related keywords that express the same search intent fall into the same segment.

For example, the terms flight cost comparison and compare flight prices fall into the same segment. Whereas the term Flight cost calculator, belongs in a separate segment because the action the searcher wants to carry out isn’t the same.

Example of keyword segmentation

Both searchers are looking to optimize their costs. However, the searcher in column A is working out the most cost-effective route for a journey. The searcher in column B intends to compare the prices of different airlines. Correlate your segments with the core topics you’ve identified and make sure they match.

5. Create a pillar page for each segment, or cluster optimized for the core keyword identified in step 2. If you already have content, optimize an existing page and turn it into a pillar page.

On an eCommerce site, this could be your category pages. For a content site, the pillar could be a landing page. In a blog, the pillar is the post that covers all aspects of an overarching topic.

6. Create additional content around the pillar. Select the most valuable keywords in a cluster by analyzing the relevant metrics, such as search volume, zero clicks, keyword difficulty, and CPC. With Similarweb, you can break down the traffic sources and analyze organic traffic separately. Go for the most valuable keywords first, and keep adding content as you go..

Screenshot of organic traffic distribution for a keyword.

See how traffic for a specific keyword is distributed among the competition to assess how valuable it is for you.

Eventually, your website will include content that targets every keyword in your cluster. Each pillar with its connected pieces forms a topic cluster.

Let’s say your pillar piece is flight comparison. You’ll then create content around long-tail keywords and subcategories, i.e., How to compare overseas flights? Another one: Best flight comparison software or Why you need to compare flight costs.

Do you see how each keyword addresses the subject with a slightly different focus? Each represents a minute shift in search intent. Creating distinct content for each allows you to target all relevant keywords in one piece. At the same time, all pages strengthen the authority of the core pillar page and support other pages in the topic cluster.

Illustration of what a content cluster looks like.

6 common mistakes when creating keyword clusters

Keyword clustering benefits your organic ranking and also organizes your site logically and intuitively for the visitor. You gradually build it one piece of keyword-focused, quality content at a time.

Watch out for the following common pitfalls. If you’re putting in the effort without seeing the desired results, check if any of the following is true for you:

1. Your research is insufficient
Keyword research is the backbone of keyword clustering. It’s critical to carry out in-depth keyword research and use tools that provide fresh, accurate data. Not doing enough research or not getting quality data can lead to investing effort in keywords that seem popular but don’t actually drive traffic. There could be many reasons, either your data was outdated, you didn’t get information on zero-clicks, you didn’t discover recent trends or rising competitors, and so on. Make sure to get fresh, high-quality data from your keyword research tool..

2. You’re inconsistent
Keyword clustering isn’t a one-time project. If you want to keep developing the cluster structure, keep researching and optimizing. New keywords enter the web, seasonality impacts search volume, events cause disruption, just to name a few factors. SEOs who don’t adjust the clusters and keep adding, removing, and shifting priorities with demand are less happy with the organic traffic performance.

3. You’re not leveraging the linking possibilities
Many site owners link pages only to the relevant pillar page. This means missing out on additional opportunities to strengthen their SEO and authority. Interlink the pages inside a cluster and, when relevant, also link to other clusters. Google algorithms are smart enough to understand the connections.

4. You’re the victim of keyword cannibalization
Keyword cannibalism occurs when two pages target the same exact keyword and search intent. This confuses search engine crawlers, and Google doesn’t know which to index.

You might think keyword clustering increases the risk of cannibalization. However, with thorough research, smart segmentation, and SEO-focused content creation, each piece of content targets a unique core search term.

5. Your pillar pages are too general or too deep
Often people believe their pillar pages do not need to include much information. They keep them general because the in-depth information is in the cluster content pages. On the other side of the scale there are content creators that load so much information onto a pillar page and overwhelm the readers. You need to find the golden path in the middle. Provide highly relevant, comprehensive content and high quality. It needs to be long and informative enough for Google to recognize it as a pillar but still be digestible by the average reader.

6. You’re not updating your content frequently
We’ve already talked about consistency and the need to keep optimizing. Not updating content harms ranking and counteracts keyword clustering. Sometimes it’s more beneficial to repurpose or update existing content. Google doesn’t appreciate outdated content.

5 reasons you should use keyword clustering

Five reasons to use keyword clusters

1. Your pages will rank for multiple keywords.
Your pages rank for multiple keywords when you apply keyword clustering. This increases the visibility of your content and chances of getting found.

2. You get more organic traffic.
A page that ranks for multiple keywords brings in significantly more traffic because it shows up more often on the SERP. Keyword clustering significantly increases traffic potential.

3. You get more traffic for long-tail keywords.
Keyword clusters increase your chances of getting traffic for long-tail keywords and, in turn, help you rank for short-tail keywords with a high keyword difficulty score faster.

4. You’ll understand search intent better.
You’ll better understand your audience’s behavior through keyword research when building keyword clusters. You can get more specific targeting and optimize digital marketing strategies and product offerings.

5. You can filter out irrelevant keywords.
During keyword research, you can identify keywords that don’t fit in any cluster, target a different intent, or serve only a specific geographical region. Decide if their potential justifies creating content or dump them.

Creating content clusters from the keyword clusters has additional advantages:

6. Your site receives an optimal structure for organic search.
Search engines love structured websites because they are easier to crawl. The keyword cluster structure is an ideal foundation to keep growing your website in a structured and SEO-friendly manner.

7. Your content, page, and domain authority increase.
With keyword clustering, pages support and supplement each other. Over time your site gains visitors’ respect, and Google recognizes your authority on relevant topics.

8. Your pages rank faster.
When you create content clusters that form around related keywords, search engines can quickly identify the search intent and index new pages faster.

9. You get more possibilities for internal linking.
Keyword clustering is a fantastic way to add internal links. All pages link back to the pillar and interlink within the cluster.

Your Turn to Find Keywords for Your Clusters

Keyword clustering matches the way Google reads and understands your site content. Keyword research enables you to meet the search engine’s demand and guide the right audience with the desired search intent toward your content.

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