13 min read

The Ultimate Guide to Secondary Keywords in SEO

A person's hands typing on a laptop, illustrating the process of finding secondary keywords.

In the world of SEO, it’s easy to fixate on a single, perfect keyword. But focusing on just one primary term is like fishing with a single line. To truly succeed, you need to cast a wider net. This is where secondary keywords come in. They are the supporting terms, related questions, and synonyms that give search engines the full picture of your content.

Understanding how to find and use these keywords is a game changer. It helps Google connect your content with a much broader range of search queries, boosting relevance and driving more traffic. This guide breaks down everything you need to know about secondary keywords, from what they are to how you can use them to climb the search rankings.

What Are Secondary Keywords?

Secondary keywords are search terms that support and add context to your primary keyword. Think of them as subtopics or different ways of phrasing the main idea. For example, if your main topic is “improve SEO,” your secondary keywords might include “how to improve SEO” or “SEO improvement tips”. They are not just random additions; they are strategically chosen phrases that enrich your content and signal to search engines that your page offers a comprehensive answer.

While you might hear terms like LSI or semantic keywords, these essentially describe related terms that provide context. In fact, Google’s John Mueller has clarified that there is no such thing as LSI keywords in their algorithm. The main goal is simply to use related concepts that make your content more thorough and helpful.

Why Are Secondary Keywords So Important?

Leveraging secondary keywords is a fundamental part of a modern content strategy. Here’s why they matter so much.

  • You’ll Reach a Wider Audience: A single page can rank for hundreds or even thousands of different keywords, not just one. By including secondary keywords, you open the door for your content to appear in a much wider variety of search results.
  • They Clarify Your Intent for Search Engines: Modern search engines use semantic search to understand the meaning behind a query, not just the exact words. Secondary keywords help clarify ambiguous terms. For instance, if your primary keyword is “apple,” adding terms like “iPhone” and “Cupertino” signals you’re talking about the tech company, not the fruit. To go deeper, see our guide to understanding keyword intent.
  • They Help You Create Comprehensive Content: Using secondary keywords naturally encourages you to cover a topic in greater depth. Addressing related subtopics makes your content more valuable to readers and demonstrates your expertise and authority to Google, which is great for EEAT (Experience, Expertise, Authoritativeness, and Trust).
  • They Drive More Traffic and Conversions: By targeting a wider range of queries, you naturally attract more visitors. Many secondary keywords are long tail phrases (three or more words), which are used in the majority of Google searches. These specific queries often have higher conversion rates because users are further along in their decision making process.
  • You Gain a Competitive Edge: Many competitors still focus narrowly on one or two major keywords. By creating comprehensive content rich with secondary keywords, your page can become the go to resource that outranks thinner, less detailed articles.

How to Find Secondary Keywords

Finding the right secondary keywords is a mix of using smart tools and understanding what your audience is looking for. Here are a few proven methods to build your list.

1. Use Google Search Itself

Google is your best free tool for discovering what people are actually searching for.

  • Google Autocomplete: Start typing your primary keyword into the search bar. The suggestions that appear are popular, real user queries and perfect candidates for secondary keywords.
  • People Also Ask (PAA): This box shows questions related to your search. Each question is a secondary keyword that you can answer in your content, often as a subheading.
  • Related Searches: Scroll to the bottom of the search results page to find a list of related queries. This section can reveal different angles you hadn’t considered. Understanding these Google SERP features helps you spot opportunities systematically.

2. Mine Your Google Search Console Data

Google Search Console (GSC) is a goldmine for finding secondary keywords that your site is already getting impressions for. Go to the “Performance” report and look at the “Queries” tab. Here you will find terms bringing users to your page. Look for keywords with high impressions but a low average position, for example, positions 11 to 30. These are your “striking distance” keywords, and optimizing your content to better include them can provide a quick ranking boost.

3. Check Top Ranking Pages

Your competitors on page one are a great source of information. Analyze their content to see what secondary keywords they target. You can use SEO tools like Ahrefs or Semrush to enter a competitor’s URL and see all the keywords that page ranks for. If you’re exploring tool options, see our guide to Ahrefs alternatives. Look for common themes or subheadings they use. If multiple top pages cover a specific subtopic, that’s a strong signal you should include it too.

This process can be time consuming, but it provides a proven roadmap. For businesses looking to scale this effort, AI powered SEO services like Rankai can automate this competitive analysis, ensuring your content covers all the critical angles.

4. Use a Keywords Explorer Tool

Dedicated keyword research tools can supercharge your efforts. Tools like Ahrefs, Semrush, and Moz allow you to enter a primary keyword and receive hundreds of related ideas, complete with data on search volume and difficulty. If you want to speed this up with automation, compare the best AI keyword research tools.

For those on a budget, free tools like AnswerThePublic can generate a visual map of questions and phrases related to your topic. Google’s own Keyword Planner is another solid free option that provides lists of related terms.

5. Use Content Optimization Tools

Content optimization software like Surfer SEO or MarketMuse works by analyzing the top ranking pages for your primary keyword. These tools scan the content of your competitors and generate a list of important terms and phrases they frequently use. This list is a ready made collection of proven secondary keywords. By ensuring your content includes these terms, you can create a more comprehensive article that has a higher probability of ranking well.

6. Tap into Forums and Your Own Expertise

Sometimes the best secondary keywords come from real conversations. Browse industry forums like Reddit, Quora, or specialized online communities. Pay attention to the exact language and questions people use when discussing your topic. This is the authentic voice of your audience. Your own experience is also valuable. Think about the common questions clients ask or the follow up topics that always come up in conversations. These real world insights often reveal valuable long tail keywords that SEO tools might miss.

How to Use Secondary Keywords in Your Content

Once you’ve found your keywords, the next step is to weave them into your content naturally. Here are the key rules to follow.

Rule 1: Include Keywords Naturally

Your primary goal should always be to write for your human audience, not for search engine bots. Secondary keywords should fit seamlessly into your sentences. If a phrase feels forced, it will hurt the reader’s experience, which can lead to higher bounce rates and signal poor quality to Google. They work great in subheadings (H2s and H3s), image alt text, internal links, and meta descriptions, as long as they make sense. If you’re unsure about internal link density, use this practical guide on how many internal links per page.

Rule 2: Prioritize the Primary Keyword

While secondary keywords are important, your primary keyword is still the star. It should be featured in the most critical on page SEO elements to make the page’s main topic clear.

Make sure your primary keyword appears in the:

  • Title Tag: The main title in search results.
  • URL Slug: The part of the URL that identifies the page.
  • Main Heading (H1): The primary headline on the page itself.
  • Introduction: Mention it within the first paragraph.
  • Meta Description: This can improve click through rates.

Secondary keywords should be used to support the main topic in the body of the content. If the basics are not set up correctly, run a technical SEO audit to uncover issues fast.

Rule 3: Target Multiple Phrases on One Page

A single, comprehensive page should be optimized for a primary keyword and a cluster of related secondary keywords. This is much more effective than creating dozens of thin pages targeting minor variations. For example, a page about “best running shoes” can and should also target “lightweight running shoes” and “running shoes for flat feet.” This shared vocabulary signals to Google that your page is a thorough resource.

Rule 4: Avoid Keyword Stuffing

Keyword stuffing is the outdated practice of cramming a page full of keywords to manipulate rankings. This is a direct violation of Google’s spam policies and can get your site penalized. It also creates a terrible user experience. Instead of repeating the same phrases, focus on variety. It’s better to use ten different secondary keywords once than to use one secondary keyword ten times.

Monitoring and Iterating on Your Keyword Strategy

SEO is not a “set it and forget it” activity. After you publish, it’s crucial to monitor performance to see which keywords are gaining traction.

Using Google Search Console, you can track the average position for the queries your page ranks for. Pay attention to which secondary keywords are driving impressions and clicks. If a page is not performing well after a few weeks, it may need to be refreshed or rewritten. This iterative process of publishing, monitoring, and optimizing is key to long term SEO success.

You will often hear “related keywords” used interchangeably with secondary keywords, and while they overlap, there is a slight difference.

  • Related Keywords are terms that are semantically connected to your main topic. For the keyword “fitness,” related terms would be “exercise,” “workout,” and “nutrition”. They help clarify context.
  • Secondary Keywords are defined more by their strategic role. They are any keywords you target on a page that are not the primary one. This can include related keywords, but also subtopics that expand the page’s scope.

In practice, a good SEO strategy uses both. The goal is to create content that is both contextually clear and comprehensive.

Secondary Keywords vs. Long Tail Keywords

It’s also easy to mix up secondary keywords and long tail keywords. Here’s the distinction:

  • Long Tail Keyword describes the length and specificity of a query. These are typically phrases of three or more words, like “best running shoes for flat feet.”
  • Secondary Keyword describes its role and priority on your page. It’s any keyword that supports your primary focus.

Often, your best secondary keywords will be long tail keywords. For a page targeting the broad keyword “digital camera,” you would use long tail secondary keywords like “best digital camera for beginners” to capture more specific searches. Grouping them into keyword clusters helps structure your content effectively.

Secondary Keyword Examples

Let’s look at how this works in a few different industries.

Healthcare Example

  • Primary Keyword: “Diabetes Management”
  • Secondary Keywords: “blood sugar control tips,” “type 2 diabetes diet plan,” “signs of high blood sugar,” “managing diabetes complications.”
  • Why it Works: A comprehensive article on diabetes management must cover these subtopics to be truly useful. This strategy allows the page to rank for a wide array of queries from people at different stages of their health journey.

Finance Example

  • Primary Keyword: “Credit Score Improvement”
  • Secondary Keywords: “how to improve credit score fast,” “what factors affect credit score,” “how to remove errors from credit report,” “building credit from scratch.”
  • Why it Works: People searching for financial advice have very specific questions. By including these secondary keywords, a single article can serve as a complete resource for capturing hundreds of these niche, long tail queries.

Ecommerce Example

  • Primary Keyword: “Running Shoes”
  • Secondary Keyword: “best running shoes for flat feet,” “long distance running shoes,” “trail running vs road running shoes,” “women’s lightweight running shoes.”
  • Why it Works: An ecommerce category page or buying guide needs to target the specific phrases shoppers use. Someone searching for “best running shoes for flat feet” is a highly qualified buyer. Optimizing for these terms drives targeted traffic that is more likely to convert.

Conclusion: Put Secondary Keywords to Work for You

Mastering secondary keywords is what separates basic SEO from an effective content strategy. By moving beyond a single primary keyword, you create content that is more valuable for your audience and more visible to search engines. This leads to higher rankings, more organic traffic, and better business results.

While this process requires research and ongoing monitoring, the payoff is enormous. If you’re looking to implement this strategy at scale, an AI first SEO service could be the answer. Platforms like Rankai are built to do exactly this, combining AI efficiency with human expertise to produce highly optimized content. Their unique “rewrite until it ranks” model ensures your content is always working to capture the full spectrum of relevant keywords.

Whether you tackle it yourself or with a partner, the message is clear: stop fishing with a single line. Cast a wider net with secondary keywords and watch your organic traffic grow.


Frequently Asked Questions (FAQ)

1. What is the difference between primary and secondary keywords?
A primary keyword is the main topic of your page and should be featured in key places like the title and H1 tag. Secondary keywords are related terms and subtopics that you weave into the body content to add depth and context.

2. How many secondary keywords should I use on a page?
There is no magic number. Instead of focusing on quantity, focus on covering the topic comprehensively. A long, in depth article might naturally include dozens of secondary terms, while a shorter post may only have a few.

3. How do I know if my secondary keywords are working?
You can use Google Search Console to monitor performance. Check the “Queries” report for your page to see which secondary keywords are getting impressions and clicks. An increase in rankings or traffic for these terms is a positive sign.

4. Does using secondary keywords guarantee higher rankings?
No single SEO tactic guarantees rankings. However, using secondary keywords effectively is a core part of creating high quality, comprehensive content, which is a major factor that search engines like Google reward.

5. Are secondary keywords still important with Google’s AI updates?
Yes, more than ever. Google’s AI is designed to understand topics holistically. Using secondary keywords helps you create the kind of in depth, contextually rich content that these advanced algorithms reward. If you’re tracking how AI is changing results, see our complete guide to Google AI Overview.

6. Where can I find secondary keywords for free?
You can find excellent secondary keyword ideas for free by using Google’s Autocomplete, the “People Also Ask” boxes, and the “Related Searches” section. Google Search Console is another powerful free tool for finding keywords you already have some visibility for.