How to do keyword research: step by step with free tools

Keyword research means finding out which words your customers search with, with what intent, and which page answers them. You do it in five steps with free Google tools: collect your customers' words, add to them from four free sources, determine the search intent, group them into pages and prioritise.

The result is not a long list of words, but a short list of pages in the order you build them. That applies whether you do it yourself or hire an SEO agency. The examples come from Google Suggest, queried from Belgium on 27 September 2026; they are Dutch-language searches, with an English translation in brackets.

Step 1: start with your customers' words

Google recommends it in its own SEO Starter Guide: think about the words someone would use to look for your content, because experts search differently from beginners ^[1]. You find those words in quote requests and emails, in the questions your front office gets every week, and from your sales staff and technicians.

Write everything down, unfiltered. You don't need to anticipate every variant: according to Google, its language systems also understand searches that don't use your exact words ^[1].

Step 2: add to them from four free sources

Search in Suggest from Belgium and in a private window, and type a letter after your topic ("dakisolatie a", roof insulation). In Keyword Planner, set the location to Belgium or your province and the language to Dutch or French; no campaign needs to be running ^[3]. The top-of-page bid range shows the commercial value of a search term ^[3].

In Search Console, searches with many impressions and few clicks, or with a position just outside the top 10, are your quickest wins. Paid suites such as Semrush cost from $139.95 per month ^[7]; you don't need them for a first round of research.

Step 3: determine the search intent

• Informational ("dakisolatie dikte", roof insulation thickness; "chauffagist betekenis", heating engineer meaning): an article or explanation.
• Comparison ("warmtepomp lucht water", air-to-water heat pump; "warmtepomp prijs", heat pump price): a comparison or pricing page.
• Transactional ("opritten aanleggen", driveway installation; "klinkers leggen prijs per m2", paving price per m2): a service page with a clear call to get in touch.
• Local ("tuinaanleg in de buurt", landscaping near me; "chauffagist aalst", heating engineer Aalst): a service page and your Google Business Profile.
• Navigational (your brand name with "contact" or "opening hours"): your homepage or contact page.

The best check is the search results page itself. If Google mainly shows explanations and videos for "klinkers leggen op stabilisé" (laying pavers on a stabilised sand base), don't build a sales page. If it shows businesses and a map for "opritten aanleggen", that is where your service page belongs.

Step 4: group search terms into pages

Search terms that ask the same question, such as "dakisolatie prijs", "prijs dakisolatie per m2" and "wat kost dakisolatie" (all about the cost of roof insulation), share one page. Google calls pages that exist only to rank for similar searches doorway abuse, and pages created at scale without value of their own scaled content abuse ^[8]. Length is not a goal: according to Google, the length of content alone doesn't matter for ranking ^[1].

That is how your keyword map comes together: per topic, the search terms, the intent, the page and a priority. Commercial search terms belong on your service pages, informational questions in articles that link to those service pages.

Step 5: prioritise on volume, value and feasibility

Start with the clusters that score 7 to 9 points. "Dakisolatie premie 2026" (roof insulation grant 2026) ranks higher in Suggest than "dakisolatie prijs" (roof insulation price), but it is informational and can wait until your service page is live.

Which clusters will pay off first for your site, you can see in the free SEO scan. If you are building a new website, do this research before the structure is fixed; my colleague Bert sets out the steps in the checklist for a new website.

Belgian pitfalls, and the bridge to Google Ads

• Flemish words. People in Flanders search for "chauffagist", "kinesist" and "garagepoort" (heating engineer, physiotherapist, garage door), not for the words used in guides from the Netherlands.
• French is a second search market, with its own questions such as "isolation toiture prime région wallonne". So redo the research in French for Brussels or Wallonia.
• Small volumes look like zero. Many valuable search terms in a single province fall below the tools' thresholds. A search term without volume can still bring in customers: look at the value of one customer.

The same map feeds your Google Ads campaigns: each commercial cluster becomes an ad group with its own ad and landing page, and words such as "vacancy" or "free" become negative keywords. Google measures that match in the Quality Score ^[9], see improve your Quality Score in Google Ads. Conversely, the search terms report shows which actual searches converted ^[10].

Repeat the research in Search Console every quarter. What SEO work based on such a map costs is covered in how much does SEO cost per month; if you work in one region, start with local SEO.