Secondary Keywords: What They Are and How to Find and Use Them

In this article, you'll learn what secondary keywords are, why they matter for both traditional search and AI answer engines, and exactly how to find and use them to rank for more queries with less content. You'll also discover how to track which secondary keywords actually drive traffic—including the growing slice of visits from ChatGPT, Perplexity, Claude, and other AI search tools.

What Are Secondary Keywords?

Secondary keywords are search terms closely related to your primary keyword. They include synonyms, variations, and long-tail phrases that share the same search intent as your main target.

If your primary keyword is "project management software", your secondary keywords might include:

• "project management tools"

• "best project management software for teams"

• "project tracking software"

• "team project management app"

These terms all circle the same topic. Someone searching any of them wants roughly the same thing: a tool to manage projects. This overlap is what makes secondary keywords valuable.

When you include them naturally in your content, search engines understand that your page covers the topic thoroughly. Instead of creating five separate pages for five related terms, a single well-structured piece can rank for all of them.

The Difference Between Secondary Keywords and LSI Keywords

You'll sometimes hear secondary keywords called LSI (Latent Semantic Indexing) keywords. There's a technical distinction worth knowing.

Secondary keywords are direct variations of your primary keyword—synonyms and close reformulations. LSI keywords are conceptually related terms that aren't necessarily synonyms. For "apple" the fruit, LSI keywords might include "orchard," "vitamin C," and "honeycrisp." These aren't ways people search for apples, but they signal to search engines which "apple" you're writing about.

LSI keywords help with disambiguation. Secondary keywords help you rank for multiple queries. Both matter, but secondary keywords have the bigger direct impact on traffic because people actually search for them.

The rest of this guide focuses on secondary keywords—the terms that can bring visitors to your page.

Why Secondary Keywords Matter for SEO

Secondary keywords expand your reach without expanding your workload. Here's what that means in practice.

You Rank for More Queries With Less Content

A single article optimized for secondary keywords can capture traffic from dozens of related searches. This is more efficient than the old approach of creating separate pages for each keyword variation—which often leads to thin content and internal competition.

Google's algorithm updates over the past decade have reinforced this. The Hummingbird update (2013) taught Google to understand search intent, not just match exact keywords. The BERT update (2019) improved understanding of context and natural language. Both changes reward content that covers a topic thoroughly rather than content that repeats one keyword obsessively.

You Clarify Ambiguous Topics

Some primary keywords are ambiguous. "Mercury" could mean the planet, the element, or the car brand. "Python" could mean the snake or the programming language.

Secondary keywords resolve this ambiguity. If your secondary keywords include "syntax," "libraries," and "data analysis," search engines know you're writing about Python the language. If they include "habitat," "species," and "venom," you're writing about the snake.

This clarity helps you rank for the right searches and avoid showing up for irrelevant ones.

You Build Topical Authority

Search engines don't evaluate pages in isolation. They look at your entire site to assess whether you're an authority on a topic.

When you use secondary keywords well, you demonstrate comprehensive knowledge. Your content addresses the full scope of what someone might want to know, not just one narrow slice. This depth signals expertise, which can lift rankings across all your related content.

How Secondary Keywords Work in AI Search

Everything above applies to traditional search. But there's a parallel channel growing fast: AI answer engines like ChatGPT, Perplexity, Claude, and Google's AI Overviews.

These tools synthesize information from multiple sources and present a direct answer. The sources they cite get mentioned—and increasingly, they get traffic.

Secondary keywords matter here too, but the mechanism is different.

AI Engines Pull From Comprehensive Content

AI models are trained on—and in some cases, actively retrieve from—web content. When someone asks Perplexity "what's the best project management software for small teams," the model looks for content that addresses that specific question thoroughly.

Content that covers secondary keywords naturally tends to be more comprehensive. It answers not just the primary question but related questions the user might have. This comprehensiveness makes your content more likely to be cited or surfaced.

Prompts Mirror Secondary Keywords

Users don't query AI engines the same way they query Google. They ask full questions in natural language:

• "What project management tools work best for remote teams?"

• "Compare Asana vs Monday for marketing agencies"

• "Which project tracking software has the best free tier?"

Each of these is essentially a secondary keyword in prompt form. If your content addresses these specific angles, it's more likely to be cited when those prompts are asked.

This is where AI search analytics tools become valuable. Just as you use Google Search Console to see which queries drive traffic from traditional search, you can use tools like Analyze AI to see which prompts mention your brand and which sources AI engines cite.

The Citation Pattern Differs by Engine

Not all AI engines behave the same way. Our analysis of 83,670 AI citations across ChatGPT, Claude, and Perplexity revealed significant differences:

• Claude heavily favors blog content (43.8% of citations) over product pages (10.5%)

• ChatGPT and Perplexity favor product and feature pages (60.1% and 54.3% respectively)

• ChatGPT cites Wikipedia for 12.1% of queries; Claude cites it 0.1% of the time; Perplexity doesn't cite Wikipedia at all

This means your secondary keyword strategy might need to vary by engine. For Claude visibility, comprehensive blog content matters more. For ChatGPT and Perplexity, well-structured product pages with clear feature information may have more impact.

How to Find Secondary Keywords

Now for the practical part. Here are four methods to uncover secondary keywords, starting with the simplest.

Method 1: Use Google's Free Features

Google itself is a keyword research tool. When you search for your primary keyword, Google shows you exactly what related terms people search for.

Google Autocomplete

Start typing your primary keyword in the search bar and watch what Google suggests. These suggestions are based on real search behavior—they reflect what people actually type.

Type your keyword with different prefixes and suffixes to expand the suggestions:

• "project management software for..."

• "project management software vs..."

• "best project management software..."

• "how to choose project management software"

Each variation surfaces different secondary keywords.

People Also Ask

Scroll past the first few results to find the "People Also Ask" box. These are questions related to your topic—each one is a potential secondary keyword and a potential heading in your content.    

Click on a question to expand it, and Google often adds more related questions below. You can mine this section for a substantial list of secondary keywords.

Related Searches

At the bottom of the search results page, Google shows "Related searches." These are queries similar to yours that other users have searched for.

Some will overlap with Autocomplete suggestions, but you'll usually find a few unique ones here.

Validation Check

Before using a term as a secondary keyword, search for it directly. If the search results overlap significantly with your primary keyword's results, the term works as a secondary keyword. If the results are completely different, it might be targeting a different intent and should be a separate piece of content instead.

Method 2: Use a Keyword Research Tool

Google's free features give you a starting point. Keyword research tools give you data—specifically search volume and competition metrics that help you prioritize.

Google Keyword Planner

Google's free Keyword Planner (accessible through Google Ads) shows search volume ranges and competition levels. Enter your primary keyword to get a list of related terms with data.

The search volumes are ranges, not exact numbers (e.g., "1K–10K"), but they're directional enough to separate high-volume terms from low-volume ones.

Ahrefs, Semrush, or Similar Tools

Paid tools like Ahrefs and Semrush provide more precise data and additional features. They show:

• Exact monthly search volume

• Keyword difficulty (how hard it is to rank)

• Click-through rate estimates

• SERP features present for each keyword

Most also have "related keywords" or "keyword ideas" features that surface secondary keywords automatically.

Surfer and Similar Content Tools

Content optimization tools like Surfer analyze top-ranking pages and extract the terms they use. When you create a piece in Surfer, it shows you which keywords to include based on what's already ranking.

This reverse-engineering approach ensures you're using terms that search engines already associate with your topic.

AnswerThePublic

AnswerThePublic visualizes questions and phrases related to your keyword. It's particularly useful for finding question-based secondary keywords that make good H2 and H3 headings.

The free version limits daily searches, but it's useful for initial brainstorming.

Method 3: Analyze Your Existing Search Performance

If you already have content published, Google Search Console shows which queries drive impressions and clicks—including terms you may not have intentionally targeted.

Find Underperforming Keywords

In Google Search Console, go to Performance > Search Results. Filter by page to see which queries a specific URL ranks for.

Look for queries where you're ranking position 8-20 with decent impressions but low clicks. These are secondary keywords you're almost ranking for. Optimizing your content to better address these terms can push you onto page one.

Discover Keywords You Didn't Know You Ranked For

Sometimes you'll find queries you never targeted that are already sending traffic. These are opportunities to strengthen your position—or to create dedicated content if the query is different enough in intent.

Method 4: Research AI Search Prompts

This is where traditional SEO research meets the AI search channel.

AI engines respond to prompts—natural language questions and requests. These prompts function like search queries, but they're often longer and more specific. Understanding which prompts are relevant to your business reveals a new layer of secondary keywords.

Use AI Prompt Analytics

Tools like Analyze AI let you track specific prompts and see how AI engines respond. You can discover:

• Which prompts mention your brand

• Which prompts mention your competitors but not you

• What sources AI engines cite when answering relevant prompts

This data reveals gaps. If a prompt related to your product consistently cites competitors but not you, that's an opportunity. The prompt itself is a secondary keyword you should address in your content.

Find Prompt Suggestions

Analyze AI suggests prompts based on your industry and existing tracking. These suggestions can surface secondary keywords you hadn't considered.

You can then track these prompts to see which AI engines mention your brand—and adjust your content strategy accordingly.

Check Citation Sources

When AI engines cite sources, they're telling you which content they trust for specific topics. Analyzing these citations shows you:

• Which of your pages get cited (and for which prompts)

• Which competitor pages get cited

• Which third-party sources influence AI responses

If third-party review sites or comparison pages get cited heavily, that's a signal about content format. If competitor product pages dominate citations, you know where to focus improvement efforts.

Method 5: Use Industry Knowledge and Forums

Keyword tools show you what's already being searched. Industry forums and communities show you emerging questions and terminology that may not have search volume yet.

Monitor Industry Forums and Communities

Places like Reddit, industry Slack groups, and specialized forums (like GrowthHackers for marketing or Hacker News for tech) surface questions and terminology that haven't made it into keyword tools.

These conversations reveal the language your audience actually uses. A phrase that shows zero search volume today might become a valuable secondary keyword in six months.

Interview Customers and Sales Teams

Your sales team hears how prospects describe their problems. Your support team hears how customers ask questions. This language often differs from what marketers assume.

Ask them:

• What words do prospects use to describe their needs?

• What questions come up repeatedly in sales calls?

• What alternative products do prospects mention?

This qualitative research surfaces secondary keywords that pure data analysis misses.

How to Use Secondary Keywords in Your Content

Finding secondary keywords is step one. Using them effectively is step two.

Include Them Naturally

The goal is to write content that happens to include secondary keywords—not to stuff keywords into content.

Write for your reader first. Cover the topic thoroughly. Address the questions someone might have. If you do this well, secondary keywords will appear naturally because they're part of the topic.

After writing, check your content against your secondary keyword list. If important terms are missing, look for natural places to add them. If you can't find a natural place, the term might not fit this piece.

What to avoid:

• Awkward phrasing just to include an exact keyword

• Repeating the same term unnaturally

• Adding a keyword that doesn't fit the content's purpose

Search engines are sophisticated enough to understand variations. You don't need to include both "project management software" and "project management softwares" (grammatically incorrect) to rank for both.

Place Keywords Strategically

Some locations carry more weight than others:

Headings (H2, H3)

Secondary keywords work well in subheadings. A heading like "How to Choose Project Management Software for Remote Teams" includes your primary keyword plus a secondary modifier ("for remote teams").

This serves SEO and helps readers navigate. Someone scanning your article can see at a glance that you address their specific situation.

First 100 Words

Include your primary keyword and one or two secondary keywords early in the content. This signals the topic immediately to both readers and search engines.

Image Alt Text

Describe images accurately, and where it's natural, include relevant keywords. Don't stuff keywords into alt text—it should describe what's in the image for accessibility purposes. But if the image shows project management software features, saying so in the alt text is both accurate and useful for SEO.

Meta Description

Your meta description doesn't directly impact rankings, but it affects click-through rate. Including a secondary keyword (naturally) can make your result more relevant to specific searches.

Prioritize Your Primary Keyword

Secondary keywords support your primary keyword—they don't replace it.

Your primary keyword should appear in:

• The page title (H1)

• The URL

• The meta title

• Early in the content

These are the highest-priority locations. Secondary keywords fill out the rest of your content but shouldn't crowd out your primary keyword from these key spots.

Avoid Keyword Stuffing

There's a threshold where adding more keywords hurts rather than helps. Google's spam policies explicitly call out keyword stuffing—unnaturally loading a page with keywords to manipulate rankings.

Signs of keyword stuffing:

• The same phrase appearing in every paragraph

• Lists of keywords with no context

• Hidden text (same color as background)

• Keywords that make sentences awkward

Beyond Google penalties, keyword stuffing damages readability. If your content feels unnatural to read, visitors leave quickly—and that bounce rate signal hurts rankings too.

A good test: read your content aloud. If it sounds strange or repetitive, you've probably overdone the keywords.

How to Track Secondary Keyword Performance

Implementing secondary keywords is only useful if you measure the results. Here's how to track performance across traditional search and AI search.

Track Traditional Search Performance

Google Search Console

GSC shows which queries drive impressions and clicks to your pages. After updating content with secondary keywords, monitor:

• Impressions for your target secondary keywords (are you appearing in results?)

• Position (are you moving up?)

• Clicks (is the ranking driving traffic?)

Set up a comparison period to see before/after results of your optimization work.

Rank Tracking Tools

If you want daily position monitoring, use a rank tracker like Ahrefs, Semrush, or SE Ranking. These tools track specific keywords and show movement over time.

Create a tracking list that includes your primary keyword and top secondary keywords to see how your content performs across the full cluster.

Track AI Search Performance

Traditional rank trackers don't capture AI search visibility. For that, you need tools designed for AI analytics.

Monitor Brand Mentions Across AI Engines

Analyze AI and similar tools track whether your brand appears in AI responses across ChatGPT, Perplexity, Claude, Gemini, and Copilot.

You can see:

• How often your brand is mentioned for tracked prompts

• How you compare to competitors

• Whether sentiment is positive, neutral, or negative

Track AI Referral Traffic

If AI engines cite your content, some users click through. This traffic appears in Google Analytics, but it's often miscategorized.

Analyze AI connects to GA4 to isolate AI-referred sessions, showing:

• Total AI referral traffic

• Which AI engines send the most traffic

• Which pages receive AI traffic

• Conversion rates from AI traffic vs. other sources

This closes the loop from keyword strategy to actual business results. You can see whether your secondary keyword optimization is driving not just visibility but traffic and conversions.

Identify Which Pages AI Engines Prefer

AI traffic doesn't distribute evenly across your site. Some pages get cited frequently; others never appear in AI responses.

Look for patterns:

• Do blog posts get more AI citations than product pages (or vice versa)?

• Which content formats appear most often?

• Are comprehensive guides cited more than quick-hit listicles?

These patterns inform your content strategy. If AI engines prefer a certain format, create more content in that format—with your secondary keywords built in.

Secondary Keyword Examples by Industry

To make this concrete, here are secondary keyword examples across different industries.

SaaS/Technology

Primary keyword: CRM software

Secondary keywords:

• CRM software for small business

• customer relationship management tools

• CRM platforms comparison

• best CRM for sales teams

• free CRM software

• CRM with email integration

AI prompt variations:

• "What's the best CRM for a 10-person sales team?"

• "Compare Salesforce vs HubSpot for startups"

• "Which CRM has the best mobile app?"

E-commerce

Primary keyword: running shoes

Secondary keywords:

• best running shoes for beginners

• running shoes for flat feet

• lightweight running shoes

• marathon running shoes

• running shoes with arch support

• trail running shoes

AI prompt variations:

• "What running shoes do podiatrists recommend?"

• "Best shoes for half marathon training"

• "Running shoes that help with knee pain"

Finance

Primary keyword: budgeting app

Secondary keywords:

• personal budget app

• budgeting app for couples

• free budgeting app

• budgeting app that syncs with bank

• best budget planner app

• expense tracking app

AI prompt variations:

• "What budgeting app works best with Chase bank?"

• "Best app to track spending for families"

• "Which budget app has the best security?"

Healthcare/Wellness

Primary keyword: meal planning

Secondary keywords:

• weekly meal planning

• meal planning for weight loss

• healthy meal planning

• meal planning on a budget

• family meal planning ideas

• meal prep planning

AI prompt variations:

• "How do I meal plan for a family of four?"

• "Best meal planning approach for someone with diabetes"

• "Meal planning tips for busy professionals"

Notice how the AI prompt variations are more conversational and specific than traditional secondary keywords. Both matter for a complete strategy.

Key Takeaways

Secondary keywords expand your content's reach without multiplying your workload. A single thorough piece can rank for your primary keyword plus dozens of related terms.

To find secondary keywords, start with Google's free features (Autocomplete, People Also Ask, Related Searches), then layer in data from keyword research tools. Check Google Search Console for terms you're already ranking for, and use AI prompt analytics to discover how people ask questions to AI engines.

Use secondary keywords naturally throughout your content—in headings, body text, image alt text, and meta descriptions. Your primary keyword stays dominant in titles, URLs, and the H1, but secondary keywords fill out the supporting structure.

Track performance in both traditional search (Google Search Console, rank trackers) and AI search (AI citation analytics, AI referral traffic). The goal isn't just visibility; it's traffic and conversions from both channels.

AI search is becoming a meaningful traffic source. The prompts people ask AI engines mirror secondary keywords—and optimizing for both channels with the same content is increasingly possible. The brands that understand this are building visibility that compounds across both traditional and AI search.

Track your brand's visibility across AI search engines with Analyze AI. See which prompts mention your brand, which sources get cited, and how much traffic AI engines actually drive to your site.