The category “free keyword research tool” is crowded enough that most roundups just list the same eight names with the same boilerplate. The interesting question is not which tool ranks highest in someone’s roundup. It is which tool does which part of the job, and what stack of free tools approximates what a single paid tool gives you.
The four jobs a keyword tool can do
Before the comparison, the categories. Picking the wrong tool for the job produces wasted effort that most roundups never name.
- Volume data. How many people search a given query per month, with seasonal breakdown. The job is to size the opportunity on a specific keyword. Free options exist but are deliberately fuzzy without ad spend.
- Question discovery. What related questions and phrasings does the audience use. The job is to surface the long-tail and the intent variations. Free options here are strong; AnswerThePublic and AlsoAsked specifically.
- Existing-traffic data. What queries currently send traffic to your site, and at what position. The job is to optimize the pages you already have. Google Search Console is the canonical source and is free.
- Topical graph analysis. What clusters exist in the demand graph and where the gaps to the supply graph are. The job is to decide which pages to write next. Most free tools do not do this; KeywordGraph’s free trial does.
The eight tools, compared
A free stack that approximates a paid tool
Most of what a paid Ahrefs or Semrush subscription gives you is doable from three free tools used together. Not all of it, but enough that the subscription becomes a question of editorial capacity rather than data access.
- Google Search Console for the traffic you already have and the queries that send it. This is the highest-signal data source and most teams underuse it.
- Google Keyword Planner for volume orientation on the queries you do not yet rank for. Read the ranges as orders of magnitude, not as exact numbers.
- AnswerThePublic or AlsoAsked for the question shape that surrounds the head terms. The free quota is enough for two or three clusters per week.
- KeywordGraph’s free trial once a quarter for the demand-versus-supply gap analysis. Two weeks per quarter is usually enough to refresh the publishing plan.
The stack handles the four jobs from §1 with no paid subscription. The trade-off is editorial time spent stitching outputs together. For larger sites, that time exceeds the cost of a paid tool.
Recommendations by use case
- Solo founder, narrow niche, no budget. Google Search Console plus AnswerThePublic. Both free. Enough to plan an initial 12-page cluster.
- Agency planning a new client build. The full free stack plus the KeywordGraph trial. The trial covers the first quarter of planning at no cost.
- Existing site looking to expand. Google Search Console for what already works, plus Keyword Planner for sizing, plus the KeywordGraph trial for the gap analysis on the existing cluster.
- Publisher scaling across multiple clusters. A paid tool starts paying for itself. The free stack runs out of editorial leverage at around four to five active clusters.
Common misconceptions
Frequently asked questions
What is the best free keyword research tool?
Depends on the job. For volume data, Google Keyword Planner. For question discovery, AnswerThePublic plus AlsoAsked. For existing-traffic data, Google Search Console. For topical graph analysis, KeywordGraph’s free trial. No single tool is best for all four jobs.
Is Google Keyword Planner free?
Yes, with a free Google Ads account. The volume data appears in wide ranges (1K–10K, etc.) without active ad spend; running even a small campaign unlocks more precise numbers.
What can I use instead of Ahrefs for free?
The full free stack: Google Search Console plus Google Keyword Planner plus AnswerThePublic plus KeywordGraph’s free trial. The stack covers most of the research workflow Ahrefs supports, though competitor monitoring is weaker.
How many free keyword tools should I use?
Three to four, picked to cover the four jobs in §1. Using more than four free tools usually produces duplicate data and editorial overhead that exceeds the value.
Does Google have a free keyword tool?
Yes — Google Keyword Planner for volume, Google Trends for relative interest over time, Google Search Console for existing-traffic data. All three are free and primary-source. Most teams use only the Planner and miss the other two.