What is Keyword Research in SEO?

Keyword research is the process of identifying the exact words and phrases your target audience types into search engines. Done well, it tells you what to write, how to frame it, and which pages are worth creating in the first place. It is the foundation of any content or SEO strategy: if you do not know what people are searching for, you are guessing.

Why does keyword research matter?

Search engines match queries to pages. If your page does not contain the language your audience uses, it will not appear, regardless of how good the content is. Keyword research closes that gap. It aligns your content with real demand, so the traffic you earn is from people who are actively looking for what you offer.

Beyond traffic volume, keyword research also reveals intent. The same topic can be searched in dozens of ways, and the words someone chooses tell you exactly where they are in their decision-making process. "What is SEO" signals curiosity. "SEO agency London" signals purchase intent. Those two pages need to be completely different.

What are the core keyword metrics you need to understand?

Evaluating a keyword means looking at several data points, not just one.

Search volume is how many times a term is searched per month, on average. High volume means high potential traffic, but also higher competition. Volume figures vary by tool and are estimates, not exact counts.

Keyword difficulty (sometimes called KD) measures how hard it will be to rank for a term. It is typically expressed as a score from 0 to 100. High difficulty terms are dominated by authoritative sites with strong backlink profiles. New or smaller sites should target lower-difficulty keywords first.

Search intent is arguably the most important metric, even though it is qualitative rather than numerical. There are four types:

• Informational: the user wants to learn something ("how does SEO work")
• Navigational: the user wants to reach a specific site ("Google Search Console login")
• Commercial: the user is researching before buying ("best SEO tools 2026")
• Transactional: the user is ready to act ("buy SEO software", "hire SEO agency")

Matching your page type to the intent behind the keyword is critical. A product page cannot rank for an informational query, and a blog post rarely converts transactional traffic.

CPC (cost per click) is what advertisers pay to appear in paid search results for a keyword. A high CPC is a reliable signal that the keyword has commercial value. Even if you are targeting it organically, a high CPC tells you that businesses are willing to spend money on this traffic, which means it converts.

Click-through rate is the proportion of people who actually click an organic result after running a search. Some queries are dominated by SERP features: featured snippets, local packs, knowledge panels, or shopping results. These absorb clicks before users reach the organic listings. A keyword with 10,000 monthly searches but a low click-through rate may deliver far less traffic than the volume suggests. Check the SERP for each keyword before committing to it.

What are the different types of keywords?

Keywords are typically grouped by length and specificity.

Head terms are short, broad keywords: one or two words, often very high volume, and extremely competitive. "SEO", "keyword research", "ecommerce". These are hard to rank for and often have unclear intent. They are useful for brand awareness but rarely drive conversion.

Mid-tail keywords are more specific: two to four words, moderate volume, clearer intent. "What is technical SEO", "keyword research tools", "local SEO for restaurants". More achievable for sites building authority, and much clearer in terms of what the searcher wants.

Long-tail keywords are highly specific phrases, often five words or more: "how to check canonical tags across a site", "best free keyword research tools for small businesses", "local SEO checklist for new businesses". Individually, these have low search volume. Collectively, long-tail keywords account for the majority of all search traffic. They are also far more likely to convert, because the specificity signals clear intent.

A well-built content strategy targets a mix: a small number of competitive mid-tail terms for authority and reach, and a large volume of long-tail terms for consistent, high-intent traffic.

How do you do keyword research step by step?

Step 1: Identify your seed keywords

Start with the core topics your business or site covers. These are not keywords yet, they are themes. A plumber in Manchester might start with: boiler repair, emergency plumber, central heating, burst pipe. An SEO agency might start with: SEO, content marketing, link building, technical SEO. These become the foundation for your research.

Step 2: Expand using keyword tools

Feed your seed keywords into tools to generate related terms, questions, and variations. Free options include:

• Google Autocomplete: start typing a query and Google will surface the most common completions. These are real searches.
• People Also Ask: the expandable question boxes in Google's search results. Each question is a potential article or section.
• Google Search Console: shows you the queries your site already appears for, including ones you may not have deliberately targeted.
• AnswerThePublic: generates question-format variations of any seed keyword.
• Semrush free tier and Ahrefs free tools: both offer limited but useful keyword data without a paid subscription.

Step 3: Evaluate each keyword

For every candidate keyword, assess: search volume (is there enough demand?), difficulty (can you compete?), and intent (does this match what your page offers?). Ignore keywords that fail any of these tests.

Step 4: Group by intent and topic

Keywords that share the same intent and topic should be grouped together. This forms the basis of your topical authority structure: a pillar page targeting a broad term, supported by cluster articles targeting related sub-questions.

Step 5: Map keywords to pages

Each page on your site should have one primary keyword, with supporting or related keywords included naturally throughout. Do not force multiple competing primary keywords onto a single page. This is how keyword cannibalisation starts.

Step 6: Identify competitor gaps

Look at which keywords your competitors rank for that you do not. These represent existing demand that you are currently missing. Gap analysis is one of the fastest ways to find high-opportunity keywords.

What is keyword cannibalisation and why does it matter?

Keyword cannibalisation occurs when two or more pages on your site target the same primary keyword. Instead of one strong page ranking, you have two weaker pages competing against each other. Google has to choose which to show, and the signal is split between them, which means neither ranks as well as it should.

The fix is to consolidate: either merge the pages or clearly differentiate them by intent. Use canonical tags where appropriate, and ensure your internal linking consistently points to the page you want to rank for a given term. Crawly can surface pages sharing the same title or H1 text, which is often a reliable indicator of cannibalisation.

How does search intent connect to content strategy?

Keyword research tells you what to write. Search intent tells you how to write it.

A keyword like "what is on-page SEO" has informational intent. The page that ranks for it needs to define the term clearly, cover the key concepts, and give the reader enough to understand the topic. A keyword like "on-page SEO checklist" has commercial-informational intent: the user wants a practical resource they can apply. Same broad topic, completely different content structure.

Before writing any page, run the target keyword in Google and study the top results. What format are they? How long are they? What headings do they use? The SERP is telling you what Google has determined best satisfies the intent behind that query. Your page needs to match or exceed that, not contradict it.

Learn more about structuring pages correctly in our guide to on-page SEO.

How does keyword research apply to AI search in 2026?

The rise of AI-powered search, from Google's AI Overviews to Perplexity and ChatGPT, has changed how keyword research feeds into content decisions.

Keywords still matter: AI search engines are largely grounded in search index data, and Bing rankings in particular feed ChatGPT and Grok citations. If you do not rank, you do not get cited.

But AI search favours answer-style content more aggressively than traditional search. Pages that open each section with a direct, concise answer to the question in the heading are more likely to be extracted and cited by AI models. This is the foundation of Generative Engine Optimisation (GEO): learn more in our guide to what is generative engine optimisation.

In practice, this means your keyword targeting should include question-format keywords ("what is", "how to", "why does"), and your content should answer those questions directly and specifically, not after three paragraphs of preamble.

URL structure also plays a role in how search engines interpret your content's relevance. Read our guide on how to write SEO-friendly URLs to make sure your keyword targeting extends to the URL itself.

What free keyword research tools are available?

You do not need a paid subscription to start doing effective keyword research. The following free tools cover most of the basics:

Tool	What it gives you
Google Search Console	Queries your site already ranks for, impressions, clicks, average position
Google Autocomplete	Real search suggestions based on common queries
People Also Ask	Related questions searchers are asking
AnswerThePublic	Question-format variations of any seed keyword
Semrush free tier	Limited keyword data, up to 10 queries per day
Ahrefs free tools	Keyword difficulty, search volume, SERP analysis (limited)

Search Console is particularly valuable because it shows you real performance data for your own site. If a page has impressions but low clicks, the keyword may be right but the title tag needs work. If a page has clicks but ranks in position 8 to 15, it is a candidate for improvement.

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Once you have identified your target keywords, use Crawly to audit whether your pages are technically set up to rank for them. Crawly checks title tags, H1s, canonical tags, and indexability across your full site, so you can confirm that your keyword strategy is actually reflected in your on-page implementation.