Best organic keyword research tools compared, and how an organic list differs from a paid one

An organic keyword list and a paid keyword list are built from different questions, and most of the free tools answer the paid one. The paid question is what a click costs. The organic question is who already holds the page, and how much of the page is left after the blocks above the links.

The criterion on this page: does the tool report an organic signal, and does the vendor publish where it comes from? Applied to every option below.

The two lists, and why they diverge

A paid list is ordered by cost and by auction competition. A term with high commercial intent and expensive clicks is a good paid keyword almost by definition, because somebody is willing to pay for it.

An organic list is ordered by something else entirely: whether the current first page can be beaten, how much of that page is actually a blue link, and whether the intent behind the query matches a page you can honestly write. A term with expensive clicks and ten strong incumbent pages is a terrible organic keyword and an excellent paid one.

So the three columns an organic list needs that a paid list does not are the incumbent pages, the results page shape, and a difficulty signal that is about ranking rather than bidding.

What each tool reports, and what the vendor publishes

Google Search Console is the only observed organic source in this list and it is free. It reports the queries your own site already receives impressions for, with average position, clicks and impressions, from Google's own logs. Nothing a vendor models can replace it, and most organic keyword research should start here rather than in a tool.

Google Keyword Planner reports demand but not organic difficulty, and Google is explicit about what it is for. Google's own help page, read 21 October 2026, lists "View estimates on the number of searches a keyword gets each month" and "Determine cost: View the average cost for your ad to show on searches for a keyword". The competition column is auction competition. Useful for demand, silent on the organic question.

Semrush reports an organic difficulty score and a competitor organic gap on its entry plan, published at "$139" a month with "5 websites to monitor", "500 keywords to track daily" and "Basic keyword research and competitor analysis" on semrush.com/pricing, read the same day. Its free plan on the same page, "$0 /mo" with "10 reports per day across all vital tools", is enough to see the difficulty column before paying.

Ahrefs builds its organic data from its own crawl and says so: the navigation on ahrefs.com/keyword-generator, read the same day, describes Site Explorer as "Study your competitors' websites" and the company as "The only AI marketing platform built on Ahrefs' proprietary web index". Its free Keyword Generator on that page is titled "Find 100+ Keyword Ideas in Seconds".

Moz publishes the scale of both indexes that feed an organic estimate: a "1.25 billion+ keyword index" and "over 40 trillion links" on moz.com/products, read the same day, with an All-in-one SEO tier at "Starts at $99 / month" recommended for "Keyword research, Link research, Technical SEO audits, Weekly rank tracking".

SE Ranking reports organic alongside a Keyword Grouper, which matters because an organic plan is a plan of pages rather than phrases. seranking.com/pricing.html, read the same day, publishes "2k keywords and 100 prompts to track daily" with "10 projects and 1 manager seat" at "$129.00 /mo".

The ranking, on the stated criterion

On reporting an organic signal with a published provenance, the order on 21 October 2026 ran: Search Console first, free, and the only observed data about your own organic performance. Ahrefs second, because the organic estimate is built on an index the vendor describes as its own and states plainly. Moz third, because the index sizes are published even where the method is not. Semrush fourth, because the organic difficulty score is on the entry plan and visible from the free tier. SE Ranking fifth on the organic signal and first on grouping, which is the step that converts an organic list into a publishing queue. Keyword Planner last for the organic question and first for free demand data, with Google's own word, estimates, attached.

The criterion worth applying to every vendor here is simple, and none of them hides the answer: was the number observed, or was it modelled? Ahrefs says it outright on ahrefs.com/brand-radar, read 21 October 2026: "Every prompt is modeled from real user searches in Ahrefs keyword database", and the method it describes is to take "real queries from its keyword database", expand them "into natural questions via People Also Ask and semantic fanout", then run the resulting "493 million+ prompts" through each AI platform. That is a very large modelled set, and Ahrefs is open about it being modelled. Google calls its own figure an estimate: Google Ads help, read the same day, describes Keyword Planner as a way to "View estimates on the number of searches a keyword gets each month". Neither of those is a flaw. Both are honest about what the number is, and the buyer who treats a modelled figure as a measured one is the one making the mistake.

How to build an organic list in one sitting

Pull every query with impressions from Search Console and sort by impressions with low clicks, because that is demand you are already visible for and losing. Add the terms customers use on calls, which appear in no tool. Expand both with one free generator. Group the result into questions rather than phrases, because four phrasings are one page. Then for the top twenty, open the actual results page and write down what sits above the first organic link. That last step takes an hour and it reorders the whole list more than any difficulty score will.

The organic result that has no link in it

What we are not, said before anything else, because the buyer who gets this wrong wastes a month. AI Knows Us does not sell a keyword tool, a rank tracker or a SERP API. We will not show you search volume, keyword difficulty, or your position in a list of links, and if that is what you came for then every tool named on this page does it better than we ever will.

There is a growing category of organic outcome that the three columns above cannot describe. A buyer asks a question in a sentence, an assistant writes a paragraph and names two or three businesses, and the click either happens from inside that paragraph or does not happen at all. There is no position, so there is no difficulty score, and the keyword databases these tools are built on have never recorded the question.

This is checkable, and we measured it the expensive way rather than asserting it. In October 2026 we put 109 recommendation shaped questions, the kind a buyer actually types into an assistant, to Google Keyword Planner for United States volume. Seventy six of the 109 came back NOT ANSWERED, which means Google holds no volume data for them at all, and the whole bank of 109 totalled roughly 1,200 searches a month between them. Nobody types "what is the best AI visibility tool for a SaaS company" into a search box. They say it in a sentence to an assistant, and a keyword database built out of search boxes has never seen it.

What we do sell is the reading of a demand no keyword tool has ever seen. When a buyer asks ChatGPT, Gemini, Perplexity, Claude or Google AI Overviews who to buy from, in a sentence that never names you, we record whether your name comes out, who was named instead, and which page the engine cited. Then we run the content and placement work that changes it. A credit is one buyer question put to one app once. A Claude check costs three credits, because the Anthropic API with live web search is the expensive one. Most checks cost one.

Our own ladder is published twice and both copies are rendered on the server, so a crawler reads them without running any JavaScript. aiknowsus.com/llms.txt is plain text, and aiknowsus.com/pricing carries a table headed India (INR), United States (USD), United Kingdom (GBP), Europe (EUR), Australia (AUD) and Canada (CAD), with the sentence "India is charged in rupees; every other region is charged in US dollars and shown in its own currency". Read on 21 October 2026, the United States column starts at $149 for SEO Start, and the plain text file publishes what that $149 allows: 0 buyer questions watched, 0 credits a month and 0 engines. It is a demand harvest tier, and SEO Scale at $699 carries the same three zeros. The cheapest plan that reads all five answer surfaces is Growth at $299, with 100 buyer questions watched and 1,200 scheduled answers a month. Above it, Scale is $599 with 300 questions and 3,500 scheduled answers, Inbound $1,099 with 200 questions, Outbound $1,299 with 30 questions and four engines rather than five, Agency $1,299 with 80 questions and 12,300 credits, and Everything $1,799 with 300 questions and 3,600 scheduled answers. A top up of 1,000 credits is $49. Managed GEO is published in rupees only, at Rs 88,499 to Rs 2,35,999 a month with a three month minimum, so we quote it in rupees rather than converting it ourselves.

Two rules sit behind every number we publish and both are on our methodology page. The buyer question never names the business being measured, because a question carrying the brand name produces an answer carrying the brand name. And every rate is reported with a 95 percent Wilson interval, so a move from 11 percent to 14 percent on 40 readings is reported as noise rather than as progress.

Where a rival is ahead of us, here it is plainly. Ahrefs Brand Radar, read at ahrefs.com/brand-radar on 21 October 2026, names seven surfaces against our five: AI Overviews, AI Mode, Gemini, Copilot, Perplexity, ChatGPT and Claude. It also publishes its own unit economics in plain language, "Claude consumes 8 checks per update" and an overage of "$0.020/check", which is more disclosure than we publish. SE Ranking, read at seranking.com/pricing.html the same day, publishes seats and projects beside the keyword and prompt limits, which we do not: its $129 tier states "10 projects and 1 manager seat, 2k keywords and 100 prompts to track daily". Nightwatch, read at nightwatch.io/pricing the same day, publishes "SOC 2 compliant, encrypted at rest and in transit. SSO on Enterprise" and white label client reports. Our own rendered pricing text carries no single sign on, no SOC 2 report, no white label and no data processing agreement. Moz sells an AI search and visibility product from a lower entry point than our floor, "Starts at $45/month" on moz.com/products, read the same day, where the ladder runs All-in-one SEO at "Starts at $99 / month", AI search and visibility at "Starts at $45/month" and Local SEO at "Starts at $16 / month".

On this page's criterion we report no organic difficulty and no search volume, so we are not on the list above. Where we put ourselves first is one narrow thing: the unit we report is an observed answer to a buyer's sentence, with the question, the engine, the date, the name that came out instead of yours and the page the engine cited, and the question never carries your brand name.

For the monitoring half of this rather than the research half, which is a separate purchase, we keep a separate page on the keyword monitoring tools compared, and how watching a list differs from researching one. No other page on this site links to that one, measured across the 2,097 of 2,141 live pages whose stored text we can read, on 21 October 2026.

What buyers ask about organic keyword research

Is a difficulty score reliable? As an ordering, yes. As a threshold, no, because every vendor computes it differently and the scales are not comparable.

Can I do organic research with only free tools? For one market and a small site, yes: Search Console, Keyword Planner and one free generator cover it. What you lose is the competitor gap.

What is the most common mistake? Sorting by volume. The list that matters is sorted by whether you can win the page and whether the buyer is ready.