Keyword Research Tools
Keyword research tools are chosen by the question that needs answering, not by a feature list. The distinction that matters: Search Console measures your site, everything else models the market. This lesson covers which source knows what, where each one's documented limit sits, and why someone else's estimate cannot beat your own measurement.
It rests on the Search Console API usage limits and the Search Analytics query reference.
Four questions, four sources
| Question | Source | What it genuinely knows |
|---|---|---|
| Which queries do we already appear for? | Search Console | Measured impressions, clicks, CTR and average position for your site |
| Is there demand for the topic at all? | Keyword Planner | Approximate demand and the state of the ad auction |
| Which page closes the task? | The results page itself | The page formats and elements holding the top right now |
| What do competitors have that we do not? | Third-party platforms | Estimates from their own model and their own index |
No single source answers all four. Hence the rule: the question first, the tool second — not the other way round.
Search Console: what it knows and where it stops
It is the only source that measures your site rather than estimating it. Its limits are documented, and worth knowing before the work starts.
- How many rows you can pull. The Search Analytics query sets it hard: the valid range is 1–25,000 rows, the default is 1,000, and beyond that you page through with an offset. There is no "all queries" in one call.
- Which queries are expensive. The limits documentation is explicit: queries grouped and filtered by page AND query string are the most expensive, and load grows with the date range. A six-month pull broken down by page × query fails on quota where a one-week pull passes.
- How many URLs you can inspect. Index inspection has its own quota: 2,000 queries per day per site. For a 50,000-URL site that makes a full indexing check a matter of months, not an evening.
- How often you can ask. Search Analytics allows 1,200 queries per minute per site and the same per user.
Setup and first steps are in the getting started with Search Console guide. Pulling data within those limits is what Search Console export does, indexing problems are URL auditing, and the overview sits in the pages report.
Keyword Planner: it knows ad demand
An official source, but it describes advertising: volume there is an approximate 12-month average and "competition" is the share of ad slots filled. What follows for decisions is worked through in the lesson on metrics. Demand over time is read separately, in Google Trends, where the data is normalised — relative interest, not a count of searches.
The results page: it knows the format
No metric will tell you which page type a query expects; only the results will. Which elements and formats exist is listed in the search gallery; how to read intent from those signals is in the lesson on search intent. The composition of the top for your keyword is what SERP analysis breaks down, and your own page's completeness is page analysis and entity coverage.
Third-party services: they know their own model
Paid platforms earn their keep where you have no data: other people's domains, expanding a topic, overlaps with competitors. But their numbers come out of their own index and their own formula. Two practical consequences:
- An estimate of clicks on your own site always loses to Search Console: one is a measurement, the other a model.
- Metrics from different services are not comparable — each has its own scale.
Google's free set
- Search Console — queries, impressions, clicks, indexing.
- Keyword Planner — approximate demand and the ad auction.
- Google Trends — relative movement of interest.
- Rich Results Test — whether Google sees your markup; the supported types are in the gallery.
- PageSpeed Insights — field and lab speed metrics, with a public API for checks at scale.
Mistakes
- Picking a tool before stating the question.
- Trusting someone else's traffic estimate for your own site over the measurement.
- Comparing metrics from two services against each other.
- Planning exports without knowing the limits: page × query over six months will not run.
- Assuming index inspection can cover a large site.
- Buying subscriptions before the free minimum is in place.
What comes next
Tools produce numbers; a decision needs a price — what a query is worth to the business and what happens if we take it. That is the next lesson in this module.