How to do SEO keyword research: a step-by-step guide

What SEO keyword research is (and why most people do it wrong)

Keyword research is the process of finding the search terms your target audience types into Google, then evaluating which of those terms are worth targeting with content. Done well, it tells you what to write, how to prioritise your content calendar, and where you can realistically compete. Done poorly, it produces a list of phrases that either attract no traffic or attract traffic that never converts.

The most common mistake is chasing volume without thinking about competition or intent. A keyword with 50,000 monthly searches might look attractive, but if every result on page one is a major brand with decades of authority, your new page has no realistic path to ranking. Meanwhile, a keyword with 300 monthly searches and low competition might send you 200 qualified visitors a month, all of whom are ready to buy.

The second most common mistake is treating keyword research as a one-time task. Search behaviour changes. Competitors move. Google updates how it interprets intent. Your keyword strategy needs reviewing every quarter, not just when you launch a new site.

Good keyword research answers four questions: what are people searching for, how often, how competitive is it, and what do they want when they search? This guide walks you through a repeatable seven-step process that answers all four.

Step 1: Start with seed keywords

Seed keywords are the broad topic words that describe your business, product, or service. They are not the final keywords you will target. They are the starting point from which you generate a much larger list of specific, rankable phrases.

To find your seed keywords, think about the problems your business solves and the language your customers use. If you run an accountancy firm, your seeds might include: tax return, self assessment, corporation tax, VAT registration, accounting software. If you run a coffee roastery, they might be: specialty coffee, single origin beans, home espresso, coffee subscription.

Write down ten to twenty seed keywords without worrying about volume or competition. You are not evaluating them yet. You are building the raw material for the next step.

One useful technique is to write down the questions your customers ask before they buy. If they email you asking "how much should I pay for a tax return" or "what grind setting for pour over", those questions are seed keywords in natural language form. They often map directly to high-intent, low-competition long-tail phrases.

Step 2: Expand with keyword research tools

Once you have your seeds, a keyword research tool turns each one into hundreds of related phrases with volume and competition data. Two tools dominate this space for good reason.

Semrush is the most comprehensive option for most businesses. Enter a seed keyword into the Keyword Magic Tool and it returns thousands of related phrases grouped by topic, with monthly search volume, keyword difficulty score, search intent classification, and SERP feature data. You can filter by question-type keywords, by intent, by difficulty range, and by volume threshold. For anyone building a content strategy from scratch, the Keyword Gap tool also shows which keywords your competitors rank for that you do not, which is one of the fastest ways to identify content opportunities.

Ahrefs takes a different approach. Its Keywords Explorer tool is built around click data rather than raw search volume, which gives a more accurate picture of how much traffic a ranking page would actually receive. A keyword with 1,000 monthly searches but a featured snippet capturing 60% of clicks is worth far less than it appears. Ahrefs also gives you a parent topic suggestion for each keyword, helping you understand which keywords should sit on the same page rather than competing articles.

Google Trends sits alongside these paid tools and provides something they cannot: direction of travel. It shows whether a keyword is growing, declining, or seasonal. A keyword with 500 monthly searches that has doubled over the past twelve months is more valuable than one with 2,000 searches that has been falling for two years. Use Trends to validate timing and spot rising topics before they become competitive.

The process in Step 2 is simple: take each seed keyword, run it through your tools, export the results, and combine everything into a master spreadsheet. At this stage, quantity matters. You want a long list to filter down, not a short list you have pre-judged.

Step 3: Analyse keyword metrics

With your expanded list in hand, you need to evaluate each keyword against four core metrics before deciding what to do with it.

Search volume is the average number of monthly searches for a keyword. Treat it as a directional signal rather than a precise number. Tools calculate volume differently, and seasonality causes significant swings. A keyword showing 800 monthly searches might hit 3,000 in December and 200 in February. Look at trends alongside the volume figure.

Keyword difficulty (KD) is a score, typically from 0 to 100, that estimates how hard it will be to rank on page one. Lower scores mean less competition. The important caveat is that KD scores vary between tools and are based on backlink profiles of ranking pages, not the full picture of on-page quality, content depth, or domain authority. Use KD as a filter, not a guarantee. A detailed breakdown of how to interpret these scores is in the keyword difficulty guide.

Search intent describes what the person searching actually wants. Google classifies intent into four broad categories: informational (they want to learn something), navigational (they want to reach a specific site), commercial (they are researching before buying), and transactional (they are ready to buy). Targeting a transactional keyword with an informational blog post will not rank, regardless of how well the content is written. Every keyword on your list needs an intent label before you assign it to a content type.

Cost per click (CPC) is a useful proxy for commercial value. High CPC means advertisers pay a lot for that traffic, which usually means buyers are at the end of that query. A keyword with £8 CPC is more commercially valuable than one with £0.20 CPC, even if they have similar search volumes.

Step 4: Categorise by search intent

Intent categorisation turns your raw list into a structured content plan. Every keyword needs to be assigned to a content type that matches what the searcher expects to find.

Informational keywords drive blog posts, guides, and explainer pages. Phrases starting with "how to", "what is", "why does", or "when should" are almost always informational. The person searching wants an answer, not a product page. If you target these with a sales page, Google will pass you over for a page that actually answers the question.

Commercial investigation keywords sit in the middle of the funnel. Phrases like "best [product] for [use case]", "[tool] vs [tool]", and "[product] review" indicate someone comparing options before deciding. These suit comparison articles, roundups, and detailed review pages.

Transactional keywords signal purchase intent. "Buy [product]", "[product] price", "[service] near me", and brand-plus-model phrases belong to product pages and service pages, not blogs. Putting this content in a blog article creates an intent mismatch that limits ranking potential.

Navigational keywords, where someone searches for a specific site or brand, are only worth targeting if you are that brand. Otherwise, leave them alone.

AI tools can accelerate this step significantly. ChatGPT and Claude can classify a large keyword list by intent in seconds if you paste it in and ask. They are not perfect, but for a first-pass sort of 500 keywords, they save hours. Verify any that look ambiguous by checking the actual SERP for that keyword and seeing what types of pages currently rank.

Step 5: Find long-tail and low-competition keywords

Long-tail keywords are longer, more specific phrases with lower search volumes but higher conversion rates and lower competition. For most businesses, particularly new ones without established domain authority, long-tail keywords are where organic traffic actually starts.

A new site targeting "SEO tools" (240,000 monthly searches, KD 82) will rank nowhere. The same site targeting "free seo tools for small business owners" (1,200 monthly searches, KD 18) has a realistic path to page one within three to six months of publishing a well-structured article.

The maths favour long-tail. Ranking third for five long-tail keywords that each send 200 visitors a month produces 1,000 visitors. Ranking nowhere for one high-volume term produces zero. A full walkthrough of how to find and use these phrases is in the long-tail keywords guide.

To find low-competition opportunities in Ahrefs, filter your keyword list to KD below 20 and volume above 100. In Semrush, use the Keyword Magic Tool with a difficulty filter. Both tools also have a "Questions" filter that returns question-based long-tail phrases, which are particularly useful for featured snippet targeting.

Another reliable source is Google's autocomplete and the "People also ask" boxes in search results. These are real queries typed by real people. They are not always in keyword tools, which means they are often less competitive. Search for your seed keyword, note every autocomplete suggestion, scroll through the PAA boxes, and add them to your list.

Step 6: Build a keyword cluster strategy

A keyword cluster is a group of related keywords that can all be addressed on a single page, or a group that maps to a set of pages covering different angles of the same topic. Clustering is what separates a scattered content effort from a content strategy that builds topical authority.

The basic principle is this: Google rewards sites that cover a topic thoroughly, not sites that publish one good page on a topic and then move on. If you want to rank for "keyword research", you should publish a pillar article covering the full process, then supporting articles covering specific sub-topics like keyword difficulty, long-tail keywords, keyword clustering, and local keyword research. Each supporting article links back to the pillar. The pillar links out to all the supporting articles. This structure tells Google your site is a serious resource on the topic, not a site that happened to write one article on it.

To build your clusters, group your keyword list by topic using a shared theme. All keywords about keyword difficulty belong in one group. All keywords about long-tail phrases belong in another. The cluster guide at keyword clustering covers how to group, name, and prioritise your clusters so they map to a coherent site architecture.

For organising your clusters, Notion and Airtable both work well as keyword trackers. Create a database with columns for keyword, volume, difficulty, intent, assigned page, cluster, and status. This becomes your single source of truth for the content plan, and you can filter and sort it as the strategy evolves.

Step 7: Competitor keyword research

Competitor keyword research is one of the fastest ways to find proven opportunities. If a competitor ranks for a keyword and sends traffic from it, that keyword is worth evaluating. They have already done the work of proving there is demand.

In Semrush, the Keyword Gap tool compares your domain against up to four competitors and shows keywords they rank for that you do not. This produces a prioritised list of gaps you can close with new content. Filter by keywords where competitors rank in positions 1 to 10 and you have no ranking at all. These are your clearest content gaps.

In Ahrefs, the Content Gap tool does the same job. Enter your domain and up to ten competitors and it returns keywords where competitors rank but you do not. You can filter by keyword difficulty and volume to prioritise the most accessible opportunities first.

Competitor research also shows you what is working content-format-wise. If three competitors all rank with listicle-style articles for a keyword, and you publish a dense text-heavy guide, you are misreading what Google considers the right format for that query. Look at the top-ranking pages before you decide what to write, not after.

One important note: competitor keyword research should inform your strategy, not dictate it. Your competitors have different domain authority, different audiences, and different business goals. A keyword that works for them may be a poor fit for your site's stage of development. The SEO competitor analysis guide covers how to evaluate competitor data in a way that applies to your specific situation rather than just copying their approach.

Keyword research mistakes to avoid

Even experienced marketers fall into these patterns. Knowing them upfront saves months of wasted effort.

Targeting too-broad keywords too early. If your site is new or has low domain authority, competing for broad, high-volume terms is a poor use of resources. Start with long-tail and low-competition terms where you can build rankings, traffic, and authority. Move to broader terms as your site grows.

Ignoring SERP intent. A keyword's intent is defined by what Google shows on page one, not by what you assume the searcher wants. Always check the SERP before writing. If page one is dominated by product pages and you plan to write a how-to guide, either reframe the article or choose a different keyword.

Keyword cannibalism. This is what happens when you publish two or more pages targeting the same keyword. Google cannot decide which page to rank, so it ranks neither particularly well. Before publishing a new page, check whether an existing page already targets that keyword. If it does, consolidate or differentiate. The keyword clustering guide explains how to structure your pages to avoid this.

Chasing volume over relevance. A keyword with 10,000 monthly searches is worthless if the searchers are not your audience. A B2B software company targeting consumer-facing keywords will attract traffic that never converts. Every keyword you target should have a plausible path from search to business outcome.

Skipping the review cycle. Keyword research is not a one-time exercise. Search volumes change, competitors enter and exit, and Google updates what it surfaces for specific queries. Review your keyword strategy every quarter. Use Google Analytics to track which pages are gaining and losing traffic, and update your targeting accordingly.

Not tracking rankings. If you do not track where your pages rank for their target keywords, you cannot tell whether your content strategy is working. Set up rank tracking from day one. The keyword rank tracking guide covers the best tools and how to set them up correctly.

What this means for your keyword strategy

The core principle of a workable keyword strategy is specificity. The more precisely you can match a keyword to a reader's actual intent, and to a page that genuinely satisfies that intent, the better your results will be. Volume matters, but it matters less than relevance and less than competition. A keyword you can rank for is worth more than a keyword you cannot, regardless of the search numbers.

Start your process with seed keywords drawn from what your customers actually say. Expand them with tools like Semrush and Ahrefs to build a large list, then filter ruthlessly by intent, difficulty, and relevance. Build clusters around topics rather than individual keywords, and create content structures that reinforce topical authority over time.

The sites that win in organic search are rarely the ones with the biggest budgets. They are the ones with the clearest understanding of what their audience searches for and the discipline to create content that directly answers those searches, one keyword cluster at a time. If you are also working on how to improve your overall SEO performance beyond keyword research, the complete guide to improving your SEO covers the full picture.

Use Google Analytics from day one to track which pages generate organic traffic and which keywords convert. Keyword research tells you what to target. Analytics tells you what is working once you have targeted it. The two together give you a feedback loop that keeps your content strategy improving over time.

Finding low-competition opportunities that actually drive meaningful traffic is where most of the early wins come from. The low-competition keywords guide goes deep on how to identify and prioritise these before your competitors spot them. And if your business depends on local search, the local SEO keyword research guide covers how keyword research works differently when geography is part of the query.