Keyword Research for SEO: What It Is & How to Do It

What Is Keyword Research?

Keyword research is the process of finding and analyzing what relevant audiences search for in search engines like Google. So you can create content that’s more likely to rank highly in search results.

It’s a crucial part of any search engine optimization (SEO) strategy. And a helpful step to take whenever you’re planning new content.

For example, a pet retailer might conduct keyword research with Semrush’s Keyword Magic Tool. And find that:

• Thousands of people per month search “how much food should i feed my dog”
• Ranking for “royal canin dog food” is harder than ranking for “royal canin cat food”
• Most people searching “best python books” want books about coding—not snakes

This kind of information can help you spend business resources more effectively. And ultimately get more organic traffic (unpaid visits from search engines).

Why Is Keyword Research Important for SEO?

Keyword research is important for SEO because it tells you what relevant audiences are looking for and helps you prioritize ranking opportunities.

By creating content that satisfies target users’ needs, you can earn organic rankings in search results. Just like the ones below. And get more valuable traffic to your site.

Plus, using keywords on your page can help it rank higher in search engine results pages (SERPs).

Google says content relevance is one of the most important factors when ranking search results. Adding, “The most basic signal that information is relevant is when content contains the same keywords as [the] search query.”

This means it’s helpful to know the exact wording that searchers use.

How to Find Keywords

In this section, you’ll learn how to find SEO keywords that are relevant to your site.

After that, we’ll explain how to analyze and prioritize the keywords you find.

Check Your Existing Rankings

If you have a website, it might already appear for some relevant keywords. Meaning you have existing rankings to build upon.

One of the quickest ways to find out is with Semrush’s Organic Research tool.

Enter your domain, choose your target location, and click “Search.”

Then, go to the “Positions” report.

The table shows keywords you rank for and the highest position you rank in (as of the date at the top.)

If you see an icon in the “Position” column, it means your site appears in a non-standard search result known as a SERP feature.

For example, the crown icon means that you own the featured snippet (the instant answer that typically appears at the top of the SERP).

Like this:

Later, we’ll explain how to identify the best opportunities to improve your rankings. 

For now, let’s learn how to find relevant keywords you aren’t ranking for yet.

Search a Keyword Database

The most common way to conduct keyword research is to search a keyword database.

Semrush’s keyword database is the biggest on the market—it contains over 25.7 billion keywords. And you can easily search it with the Keyword Magic Tool.

Just enter a seed keyword (a term to base your search around) and your domain.

Then, choose your target location and click “Search.”

You can view five types of results: 

• All Keywords: Broad match, phrase match, exact match, and related keywords
• Broad Match: Keywords that contain any variation of your seed term with the words in any order
• Phrase Match: Keywords that contain your exact seed term with the words in any order
• Exact Match: Keywords that contain your exact seed term with the words in the specified order
• Related: Keywords that generate similar search engine results to your seed keyword

Generally, it’s best to stick with “Broad Match.”

To filter your results further, include or exclude particular terms. Using the “Include keywords” and “Exclude keywords” filters.

For example, our pet retailer might focus on “dog food” keywords that include “raw” or “natural.”

And hide keywords including brand names they don’t stock, like “royal canin.”

If you need inspiration, the list in the left-hand column shows the most common keyword modifiers. And you can filter them in or out by clicking the eye icons. 

The Keyword Magic Tool also has a dedicated filter for question keywords. 

Later, we’ll explain how to make use of all the keyword metrics you can see.

Conduct a Keyword Gap Analysis

A keyword gap analysis reveals keywords that competitors rank for but you don’t. It’s an effective way to find relevant keywords you’re missing out on.

And you can try it for free with Semrush’s Keyword Gap tool.

Just enter your domain and up to four competitors’ domains. (You can type in your competitors manually or pick the organic competitors the tool suggests.)

Then, choose your location and click “Compare.”

Scroll down to the keywords table and select “Missing.”

This shows you keywords that all competitors rank for but you don’t. So, they should be highly relevant.

To see keywords that at least one competitor ranks for but you don’t, go to “Untapped.”

These might be less relevant, but you could find some hidden gems.

Look at Search Suggestions in Search Engines

You can conduct basic keyword research by looking at search suggestions in search engines.

For example, Google offers autocomplete predictions when you start typing. And you can use this as a way to identify popular queries in your niche.

You can also note down keywords that appear in the “Related searches” sections of relevant SERPs.

And question keywords that appear in “People also ask” boxes.

Like this one:

But this method is time-consuming and provides a limited number of results.

Plus, if you want to collect useful metrics, you’ll need to import your keywords to another tool.

That’s why we recommend sticking with dedicated keyword research tools.

How to Choose Keywords

Your initial keyword research can yield thousands of keyword ideas. And not all of them will be relevant or important to your brand.

To choose the best keywords for SEO, you need to:

1. Gather useful metrics from SEO keyword research tools
2. Analyze the SERPs to see what results are shown

For the best results, we recommend working through this checklist:

Understand Search Intent

Search intent is the reason behind a user’s search.

To understand what a keyword can do for your business—and how to rank for it—you need to know the search intent behind it.

For example, people who search “pedigree small dog” typically want to purchase Pedigree-branded food for small dog breeds. So, the top-ranking results are all product pages.

When you research keywords in Semrush, you can see what type(s) of intent a keyword has.

There are four categories:

• Navigational: The user is looking for a specific page (e.g., “pedigree foundation”)
• Informational: The user is looking for general information on a topic (e.g., “can dogs eat spicy food”)
• Commercial: The user is researching their options before making the final decision on which product to buy (e.g., “best dry dog food”)
• Transactional: The user is looking for a specific product or brand, with the intention to make a purchase (e.g., “pedigree puppy food”)

You can get further insights into search intent by looking at the top-ranking results.

Just click the “View SERP” button or icon. Here’s what the icon looks like in the Keyword Magic Tool:

For example, our pet retailer might think to target “best dog food” on their dog food category page.

But all the top results are roundups from industry publications:

This suggests that it will be difficult for the pet retailer to secure a high ranking—especially with a product category page.

Instead, they can target a keyword like “dry dog food” that has commercial intent:

And a SERP containing mostly product and category landing pages:

Look at Keyword Search Volumes

Search volume tells you how many times searchers enter a particular keyword into Google per month (on average). 

The higher the search volume, the more traffic you can get if you rank well for that keyword. So, all else being equal, you should prioritize higher-volume keywords.

You’ll see volumes when doing keyword research with the Keyword Magic Tool.

And you can filter for keywords with specific volumes (e.g., over 100 searches per month).

You can look up keyword volumes for specific keywords using the Keyword Overview tool.

This tool even lets you check search volumes in specific regions (e.g., cities).

And compare search volumes across different countries.

Consider Personal Keyword Difficulty

In Semrush, keyword difficulty (KD%) measures how hard it is to rank in Google’s top 10 organic results for a given search term. 

Personal keyword difficulty (PKD%) measures how hard it is for your domain specifically. 

It considers factors like:

• The authority of your domain vs. the top-ranking domains
• Your current ranking position
• Thematic relevance between your site and the keyword (i.e., your topical authority)

The higher the score out of 100, the harder it’ll be to earn a high ranking. And therefore earn organic traffic.

For example, “healthy dog food” has a 91% keyword difficulty score.

• Chewy.com (an authoritative pet retailer) has a 22 PKD% for this keyword. If they create quality content on this topic, it should be relatively easy for them to break into the top ten.
• Theurbanpet.net (a lower-authority pet retailer) has a 76 PKD% for this keyword. To realistically compete for a high ranking, they need to improve their website authority.
• Semrush.com (a high-authority marketing site that’s unrelated to the pet industry) has a 100 PKD% for this keyword. Because the keyword isn’t relevant to Semrush’s content.

To see personal keyword difficulty scores in the Keyword Magic Tool, you’ll need to provide your domain.

Like this:

The “PKD %” column contains your personal keyword difficulty score for each resulting keyword.

It’s a good idea to focus on lower-difficulty keywords. So that you’re more likely to rank highly and see results from your SEO efforts.

Click “Personal KD %” to filter your results based on this metric.

For example, you can focus on keywords in the 0-29% range: 

Check for SERP Features

SERP features can present both an opportunity and a threat.

• Opportunity: You can rank organically for some SERP features. This can lead to more impressions and clicks, because SERP features tend to stand out and provide more information.
• Threat: Some SERP features eliminate the need for users to click on results. Or detract clicks from standard organic results (because they grab users’ attention).

So, their presence may affect your keyword decisions.

For example, the top organic result for “cat food” appears pretty far down the page:

Rather than trying to get the top organic result, you might be better off optimizing for the popular products SERP feature.

Or targeting another keyword altogether.

When you do keyword research using Semrush’s Keyword Magic Tool, you can see how many SERP features each keyword triggers.

And hover to see exactly which ones they are.

You can also click the SERP icon to view the results page for yourself. And get an idea of how much visibility each result is getting.

If you want to avoid (or pursue) keywords that trigger certain SERP features, use the filter option.

Like so:

Do a Cost-Benefit Analysis

Keyword analysis is ultimately about weighing the cost of getting a keyword ranking against its potential value.

To evaluate costs, you need to think about time and money. So, ask yourself:

• How long will it take to create and maintain high-ranking content?
• Do we have the ability to create the content in-house?
• Do we need to invest in content creation tools?
• Who will create the content and what could they be doing instead?

Now, let’s look at the benefits your optimized content could generate:

Quantifying these benefits is tricky. But as you work on your content strategy and monitor your results, you should develop a good instinct for what works for your brand.

For detailed advice, check out our guide to SEO forecasting.

How to Target Keywords

Once you’ve chosen your target keywords, make sure to record them along with any useful insights.

In Semrush, you can use the checkboxes and “+ Add to keyword list” button to save keywords in the Keyword Strategy Builder.

When you’re done with that, it’s time to develop a keyword strategy and start creating content.

Here are our top tips for success:

Do Keyword Mapping

Keyword mapping is the process of matching each target keyword with the page (or prospective page) on your site that satisfies its search intent.

It allows you to plan and optimize content more effectively.

Here’s a quick example of a keyword map in action:

Notice that we’ve grouped keywords with overlapping search intent. This is called keyword clustering, and it can help you get better SEO results.

You can streamline the process with Semrush’s Keyword Strategy Builder.

Just open one of the keyword lists you created earlier.

Then, click “Cluster this list.” 

The tool will cluster your keywords based on topic. You should target each cluster on a different page on your site. 

Use these metrics to identify the best opportunities:

• Intent: A breakdown of search intent types
• Keywords: The number of keywords in the cluster
• KD %: The average keyword difficulty score
• Volume: The collective keyword search volume

Click the arrow to see all the keywords in a cluster.

Also look at the top-performing pages for these keywords. And use them as inspiration.

All this information will help you create SEO-optimized content. As you’ll discover in the following steps.

Focus on Content Quality and Usability

Content quality is one of the most important factors in search engine rankings.

To create quality content, you generally need to:

• Satisfy search intent
• Present your content effectively
• Provide accurate and up-to-date information
• Deliver a great user experience
• Demonstrate Experience, Expertise, Authoritativeness, and Trustworthiness (E-E-A-T) 

Secondly, think about how to provide added value and stand out among your competition. That might involve doing things like:

• Covering the topic more thoroughly
• Using a new, unique angle
• Providing helpful examples
• Adding original data
• Creating original media

For example, Rover’s dog feeding guide satisfies search intent by providing detailed guidelines for various kinds of dog. 

The guide also includes lots of related information and resources. Which come from reliable sources like veterinarian Dr. Jamie Whittenburg.

Rover uses subheadings, bullet points, tables, bolding, a table of contents, and other formatting tricks to make information easier to find and digest.

And even provides a video for people who prefer to get information that way.

Use Keywords Strategically

Including keywords on your page can help it rank higher. But keyword stuffing (using keywords unnaturally) can do more harm than good. 

Here are some tips to help you get the balance right:

• Only include keywords where they read naturally
• Convert keywords into their correct grammatical forms (e.g., “Pedigree for small dogs” not “pedigree small dog”)
• Use your primary keyword in the:
  • Body content—particularly the first paragraph
  • Title tag: The page title that can appear in search results
  • H1 tag: The on-page title, which should be similar or identical to the title tag
  • Meta description: The page summary that can appear in search results
  • URL slug: The unique part of the webpage address
• Use other (secondary) keywords within the body content and subheading tags where relevant

You can also use keywords strategically when linking to your page.

Search engines use the text used for links (anchor text) to understand what linked pages are about. This means that keyword-rich anchor text can help Google understand which pages should rank for which keywords. 

For example, you might build an internal link from “/dog-food/” to “/dog-food/pedigree/” using the anchor text “Pedigree dog food.” So it’s clear which page is the most relevant result for this term.

Prioritize Keywords with Existing Rankings

Generally, it’s a good idea to optimize existing content before creating content from scratch.

Why?

• It tends to be quicker and easier
• You may have existing rankings to build upon
• The presence of poor-quality content can harm your site’s reputation and rankings
• Existing content is likely to be most relevant and important to your business

If you need help prioritizing pages and tasks, use Semrush’s On Page SEO Checker.

You set the target keyword(s) for each URL, and the tool provides:

• Optimization ideas based on best practices and top-ranking pages
• Priority ratings based on the number of ideas, keyword search volumes, and keyword difficulty scores

Advanced Keyword Research Tips

Feeling confident with what you’ve learned so far? Check out these advanced keyword research tips:

Find and Use Semantic Keywords

Semantic keywords are words and phrases that are conceptually related to a given topic.

They’re not terms that people use to search for a piece of content. They’re terms that search engines and users may expect to find within a given piece of content.

If they’re missing, it might suggest that your content is incomplete.

Let’s say you’re writing a dog feeding guide. This should probably include semantic keywords like:

• Healthy weight
• Portion size
• Senior dogs

One of the best ways to find semantic keywords is with Semrush’s SEO Content Template. 

It identifies semantically related keywords by analyzing the top-ranking results for your target keywords.

For example, here are the suggestions for “how much food should I feed my dog”:

Anticipate Keyword Trends

To get ahead of your competitors, try to anticipate upcoming keyword trends.

One of the best ways to do this is to use Google Trends. Because it tells you which search terms are gaining popularity.

For example, let’s explore the topic of “dog food” over the past 30 days.

In the “Related queries” section, we can see keywords with “the biggest increase in search frequency since the last time period.”

The percentage increase is listed on the right. (“Breakout” means that it was over 5,000%.)

By quickly creating content around these keywords, you can gain valuable rankings. Before your competitors even realize the terms are popular.

You can also anticipate keyword trends by:

• Keeping up with industry news
• Seeing what relevant communities talk about on social media
• Speaking to or surveying your customers

Keyword Research Tools

We’ve already shared some options, but let’s look at some of the best and most popular tools for SEO keyword research:

Semrush Keyword Research Tools

Here’s a quick summary of Semrush’s SEO keyword research tools (many of which we’ve discussed in this guide):

• Keyword Overview: Gather metrics for up to 100 keywords at once
• Organic Research: Enter a domain or URL to see what keywords it ranks for 
• Keyword Magic Tool: Use a seed keyword to search our huge keyword database
• Keyword Gap: Compare your keyword rankings against competitors’
• Keyword Strategy Builder: Plan effective topic clusters to target your keywords 
• Organic Traffic Insights: Combine keyword data from Google Analytics, GSC, and Semrush

Create a free Semrush account (no credit card needed) to try them out right away. You’ll also get access to other SEO tools.

SERP Gap Analyzer

Use the SERP Gap Analyzer app to find keywords competitors rank highly for with weak content. Which reveals great opportunities to get ahead.

All you have to do is enter your domain and a relevant topic. Then, wait for the app to create your report.

You’ll see a variety of keyword suggestions and a difficulty rating for each:

Click “View details” to see weaknesses in the top-ranking content. 

This gives you a good idea of what you must do to outrank your competitors.

You can then click “Generate Content” to get an AI-generated title, content brief, article, or meta description for your keyword.

Google Search Console

Google Search Console (GSC) shows up to 1,000 of the most popular keywords your site ranks for.

After signing in, go to “Performance” > “Search results.” And check all the boxes at the top.

Then, scroll down to the “Queries” table.

In addition to the keywords, you’ll see the following metrics for your selected date range:

• Clicks: The number of clicks your result was clicked
• Impressions: The number of times your search result was seen
• CTR: The click-through rate, which is the percentage of impressions that generate clicks
• Position: The average ranking of your highest result for each query

Integrate GSC with your Semrush account (along with Google Analytics) to get valuable keyword insights in one place.

Google Keyword Planner

Google Keyword Planner had long been a go-to free keyword research tool for many marketers. But it’s become increasingly difficult to get exact search volume data in the tool.

Still, it can be a valuable tool if you’re on a tight budget.

Just keep in mind that Keyword Planner is made for Google Ads users. It doesn’t provide any information about organic ranking difficulty, search intent, etc.

Google Trends

Although not exactly a keyword research tool, Google Trends can be very useful when it comes to:

• Finding trending topics
• Comparing the popularity of two or more products/services
• Estimating the long-term popularity of a keyword or topic

Track Your Keyword Rankings and Keep Improving

One of the best ways to measure the success of your keyword research and optimization strategy is to track your Google rankings.

Semrush’s Position Tracking tool makes it easy to see how things are going.

Just import your keywords from Keyword Strategy Builder (or elsewhere). 

Then, watch how your overall visibility and individual rankings change over time.

Don’t forget to keep adding new keywords as you target them.

We recommend that you conduct keyword research every few months at a minimum. So you can capitalize on new ranking opportunities and keep growing your traffic.