Ahrefs' free keyword tool versus the paid Keywords Explorer: what each one gives you

Ahrefs runs several free tools that need no account, and the keyword one is the best known. What it gives you is ideas and a volume figure. What it does not give you is the metric Ahrefs is actually famous for, and knowing which is which saves a wasted afternoon.

The criterion on this page: what does the free tool publish about its own allowance, and what does the paid product add?

The free Keyword Generator, and what it says it does

ahrefs.com/keyword-generator, read on 21 October 2026, is titled "Free Keyword Generator Tool: Find 100+ Keyword Ideas in Seconds". That number is the published allowance: a hundred or so ideas per search, which is a real quantity for one subject and not a substitute for a seat.

The same page carries a free tools list including an SEO Tools set, AI Writing Tools, an SEO Browser Extension, a Word Count tool and, first in the list we read, an AI Visibility Checker. It is worth noticing that a keyword tool vendor's free tools list now opens with a tool about whether an assistant mentions you.

The page also carries the sentence that explains the whole company: Ahrefs describes itself as "The only AI marketing platform built on Ahrefs' proprietary web index". Everything free and paid on the site is a view onto that index.

What the paid Keywords Explorer adds

Four things, and they are the reason people pay. A difficulty metric for the organic question rather than the ad auction. Traffic potential for the topic rather than volume for the phrase, which is a different and usually more useful number. The idea reports, which turn one seed into thousands of rows grouped several ways. And the parent topic, which tells you when four phrases are one page.

Alongside it, Site Explorer answers the competitor half, described in the Ahrefs navigation as "Study your competitors' websites", and Rank Tracker is described as "Monitor your rankings in search engines". GSC Insights is listed as "Monitor your rankings in Google Search Console", which is Ahrefs wrapping the free source rather than replacing it.

The one Ahrefs page worth reading before you trust any volume figure

ahrefs.com/brand-radar, read 21 October 2026, is where Ahrefs explains how it builds a derived dataset from that index, and the wording is unusually direct: "Every prompt is modeled from real user searches in Ahrefs keyword database". It then describes taking "real queries from its keyword database", expanding them "into natural questions via People Also Ask and semantic fanout", and running "493 million+ prompts" through each AI platform, with per surface counts published beside it: 277,456,152 for AI Overviews, 100,797,074 for AI Mode, 28,930,170 for Gemini, 28,921,226 for Copilot and 28,837,146 for Perplexity. The same page publishes "Claude consumes 8 checks per update", an index product at "$199 /mo" for "83 prompts/day" with "+2,500 checks/month" and an "Overage $0.020/check", and Custom Prompts from "$50/mo".

Read that paragraph and the free keyword tool makes more sense. It is a window onto a keyword database, and every product above it is that database expanded. Ahrefs is open about this, which is more than most vendors in the category manage.

The free alternatives to put beside it

Semrush publishes a free plan at "$0 /mo" with "1 demo project" and "10 reports per day across all vital tools", plus a no account Keyword Tool in its free tools list, on semrush.com/pricing, read the same day.

Moz publishes free tools including a Keyword Explorer on a "1.25 billion+ keyword index" and Link Explorer over "40 trillion links" on moz.com/products.

Google Keyword Planner is free with no report cap, and Google's own documentation describes it as a way to "View estimates on the number of searches a keyword gets each month".

Google Search Console is free and is the only one of the four reporting observed queries for your own site.

The ranking, on the stated criterion

On publishing what the free tool allows, the order on 21 October 2026 ran: Semrush first, because "10 reports per day" and "1 demo project" are exact and on the pricing page. Ahrefs second, because "Find 100+ Keyword Ideas in Seconds" is a published quantity and the method disclosure on its Brand Radar page is the most candid in the market. Keyword Planner first on a different axis, free demand data from Google's own query log with no cap. Search Console first on a third axis, observed data. Moz fourth on free allowance disclosure and first on paid entry price for AI visibility at "Starts at $45/month".

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.

The checker Ahrefs put at the top of its own free tools list

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.

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 publish no free keyword tool and no free tier, so we are last here: $149 is our floor and it watches zero buyer questions. We rank ourselves first on one narrow thing, and it is a distinction rather than a boast: our prompts are buyers' own sentences put to the live apps and recorded with the answer, so the unit is observed rather than expanded out of a keyword database. At 493 million modelled prompts and seven surfaces against our five, Ahrefs has far more of the market measured than we do.

For the full free tier comparison across vendors rather than Ahrefs alone, we keep a separate page on the free SEO keyword tools compared, and the published limit on each free tier. 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 the Ahrefs free keyword tool

Does it show keyword difficulty? The free generator is an ideas and volume tool. Difficulty and traffic potential are the paid metrics.

Do I need an account? The free tools are published as no account tools. The webmaster tools route gives more for a verified site.

Is the free volume figure the same as the paid one? It comes from the same index. What you lose for free is the depth of the idea reports and the grouping.