11 Best Free SEO Keyword Research Tools in 2026, Compared

Keyword Planner is the starting point for most free keyword research because its numbers come from Google itself. You type a seed word or a URL and get keyword ideas with monthly search-volume ranges, competition levels and a forecast of clicks and cost. It is the only tool here where the data is not an estimate from a third party, which is why paid tools are often checked against it.

The limits are real. Volume shows as a range rather than an exact figure for accounts without ad spend, and there is no difficulty score, so you cannot tell from Planner alone whether you can win a keyword. Use it to build the first list and check volumes, then take the shortlist to a tool that scores difficulty.

Ahrefs' free Keyword Generator is the fastest way to turn one idea into a list. Enter a seed keyword and you get 150 ideas — the top 100 keywords plus 50 questions — with search volume and a difficulty score for each, drawn from a database Ahrefs puts at more than 8 billion keywords. It works across Google, Bing, YouTube and Amazon, and it needs no account for a quick check.

The free version is a one-time lookup, not a workspace: only the top 10 related ideas show volume, there are no keyword lists and no exports, and daily searches are rate-limited. When the free generator runs out, the $29 Starter plan is the cheapest paid route into the full Keywords Explorer — but most bloggers will get a long way on the generator alone.

Semrush's free account is a small window into the largest keyword database in this list — more than 27 billion keywords. You get 10 reports a day across the suite, which covers Keyword Magic Tool lookups, domain overviews and keyword gap checks against competitors. That is enough to research one topic properly and to see which keywords your rivals rank for that you do not.

Ten reports a day runs out fast in a real research session, and full keyword research needs the SEO plan at $139.95 a month billed monthly — the highest entry price here. Semrush makes sense as a free tool when you want a deep look at one or two topics; as a paid tool it only pays off if you also use its audits, tracking and backlink data.

Ubersuggest is the friendliest tool in this list for beginners. The free account gives 3 searches a day, and the Chrome extension adds about 40 free lookups a day on top, which is more generous than any other free tier here. Each search returns keyword ideas with volume, difficulty and content ideas, plus a look at the sites already ranking for the term.

The data is thinner than Ahrefs or Semrush — backlink rows and tracked keywords are capped low — and rank tracking updates weekly on every plan. The Individual plan at $29 a month is the cheapest paid upgrade in this list, and the $290 lifetime option removes the monthly bill. Start free, and pay only when three searches a day stop being enough.

Moz Keyword Explorer is the easiest difficulty read in this list. Every keyword gets a volume estimate, a difficulty score, an organic click-through estimate and an opportunity score in one clean view, and Domain Authority sits next to every result so you can judge whether your site can win the term. A free Moz account includes 10 Keyword Explorer queries a month plus the free MozBar extension.

Ten queries a month runs out in a single session, so the free tier is for occasional checks, not research. The Starter plan at $49 a month adds 150 keyword queries a month and 50 tracked keywords, which is still tight for regular work. Moz is the right pick when you want the clearest possible answer to one question: can I rank for this?

AnswerThePublic answers a different question from every other tool here: not how many people search a keyword, but what they actually ask about it. Type a seed word and you get a visual map of who, what, where, when, why and how questions drawn from autocomplete data, which is exactly the raw material for article outlines and FAQ sections.

The free plan gives 3 searches a day with no signup, but it shows no search-volume or CPC data, so you still need another tool to check whether a question is worth targeting. Paid plans start at $20 a month for Starter — the old $9 and $11 prices quoted in older reviews are gone. Use it for ideas, then verify the numbers elsewhere.

KeywordTool.io mines autocomplete, so it finds the long-tail phrases people actually type — including the ones Google's own planner hides. The free version returns 750 or more suggestions per search across Google, YouTube, Bing, Amazon and other platforms, with dedicated tabs for questions, prepositions and comparisons, and no account is needed to run a search.

The catch is that the free version shows suggestions only: no search volume, no CPC and no competition data, so you cannot rank the list without paying. Pro Basic starts at $89 a month, which is steep for a suggestions-only tool. Use the free version to expand a seed word into hundreds of long-tail ideas, then check volumes in Keyword Planner or Ahrefs.

KWFinder is built around one job: finding long-tail keywords a small site can actually rank for. Its Keyword Difficulty score is the clearest in this list for beginners, and every result shows search volume, trend, CPC and the pages currently ranking, with local research across about 65,000 locations. The free plan gives 5 lookups a day.

Five lookups a day is enough for one topic, not a content plan, and KWFinder cannot be bought on its own — it comes with the full Mangools suite, starting at $61 a month billed monthly. Keyword data also runs about a month behind. Pick KWFinder when your main problem is not finding keywords, but finding ones you can win.

Google Trends answers the question the other free tools skip: is interest in this keyword rising or fading? You can compare up to five terms and see relative interest over time, by region and by season, with no account and no limits. Trending searches and breakout terms surface topics while interest is still climbing, which is when a new article has the best chance.

Trends shows relative interest on a 0 to 100 scale, not absolute search volume, so it cannot tell you how many searches a keyword gets. There is no difficulty score and no competitor data. Use it as a filter after you have a list: check the trend line before you invest a week in a topic that peaked two years ago.

Search Console is the only tool here whose keyword data is not an estimate: it shows the exact queries that already bring your site impressions and clicks, with average position for each. It is free for any verified site, with 16 months of history and no usage caps, and it updates daily.

The limit is scope: it only shows keywords your site already ranks for, so it cannot discover new topics. There are no difficulty scores and no competitor data. Its best use is finding near-miss keywords — queries where you sit on page two — because moving those to page one is usually the cheapest traffic you will ever win.

WordStream's Free Keyword Tool is the only free tool here that starts from a competitor's URL instead of a seed word. Paste a homepage and it returns keyword suggestions with search volume, competition and CPC, or enter a keyword and filter the results by industry so the numbers match your niche. The first 25 keywords show on screen, and the full list arrives by email as a CSV.

It was built for Google Ads, so the competition column measures ad competition, not how hard a keyword is to rank for organically — do not use it as a difficulty score. There is no tracking, audit or backlink tool behind it. Use it for a fast competitor peek and a first keyword list, then verify difficulty elsewhere.