Best Free Keyword Research Tools in 2026 (Compared)
Nine keyword research tools you can use without paying, what each is best at, and the free limits nobody mentions on the homepage.
You don't need a paid subscription to do good keyword research. Several tools give you real data for free, as long as you know what each one is good at and where its free plan stops.
This guide compares the best free keyword research tools in 2026: what they show, the limits of their free plans, and which combination covers long-tail ideas, search volume, questions and competitor keywords without spending anything.
Disclosure: NicheSpark is our own tool. We've listed it first because it's the free tool we built for exactly this job, and we've described every other tool as fairly as we can. Free limits change often, so we note the date we checked them: October 2026.
Quick comparison
| Tool | Best for | Free limit | Search volume? |
|---|---|---|---|
| NicheSpark | Long-tail ideas from real Google suggestions | Free, unlimited projects | No |
| Google Keyword Planner | Volume ranges straight from Google | Free with a Google Ads account | Ranges unless you run ads |
| Google Search Console | Keywords your site already appears for | Free for sites you verify | Your impressions |
| Google Trends | Seasonality and rising topics | Free | Relative interest only |
| Ahrefs Free Keyword Generator | Quick ideas with volume and difficulty | Free, limited results per search | Yes |
| Semrush (free account) | Competitor keywords and difficulty | About 10 requests per day | Yes |
| Ubersuggest | All-in-one overview for beginners | 3 searches per day | Yes |
| AnswerThePublic | Question and preposition keywords | 3 searches per day | Partly |
| Moz Keyword Explorer | Difficulty and SERP analysis | 10 queries per month | Yes |
How we chose these tools
Every tool on this list has a genuinely free option: no trial that turns into a bill, and no card required for the free part. We looked at three things: whether the data is real and useful, how far the free plan actually goes, and what kind of keyword research the tool is best suited for. No single free tool does everything, so the goal is a small stack that covers the gaps.
1. NicheSpark: best for long-tail keyword ideas
NicheSpark is a free keyword research tool that runs in Chrome. It collects the real suggestions Google Autocomplete shows, using systematic methods, and organizes them for you:
- A to Z research: your seed plus every letter, 26 queries that map a whole niche.
- Prefix and suffix research: words like best, cheap, near me or cost around your seed, with ready-made lists.
- Questions: how, what, why, can and other question words before the seed.
- Automatic organization: duplicates merged, every keyword linked to the query that found it, grouped into themes like price, local or business, and exportable to CSV.
In our mobile car detailing case study, 33 queries produced 316 unique keywords averaging almost five words each.
Free limit: none on projects or keywords. It runs one query at a time with a pause between them, so collection takes a few minutes.
Limitations: it doesn't show search volume or difficulty. Use it to discover the phrases, then check the best ones in a tool below.
2. Google Keyword Planner: best for volume from Google itself
Keyword Planner is Google's own tool for advertisers. It suggests related keywords and shows how often they're searched, using Google's data.
Free limit: it's free to use, but you need a Google Ads account, and Google asks you to complete account setup, including billing information, before you can get keyword ideas. Accounts that aren't running ads usually see volume as broad ranges, such as 1K–10K, rather than exact numbers.
Best use: checking the rough demand for a shortlist of keywords you already found elsewhere.
3. Google Search Console: best for keywords you already rank for
If you have a website, Search Console shows the real search queries people used before your pages appeared in Google, with impressions, clicks and average position.
Free limit: completely free, but only for sites you can verify you own. It can't show you other sites' keywords.
Best use: finding keywords where you already appear on page two or three and could climb with a better page.
4. Google Trends: best for seasonality
Trends shows how interest in a search term changes over time and across regions, and which related topics are rising.
Free limit: free with no account needed.
Limitation: it shows relative interest on a 0 to 100 scale, not search volume. Use it to time content and compare two phrasings, not to size a market.
5. Ahrefs Free Keyword Generator: best for a quick look at volume and difficulty
Ahrefs offers a free keyword generator built on its large keyword database. Type a seed and it returns keyword ideas with search volume estimates and keyword difficulty, and it supports several search engines beyond Google, including YouTube, Bing and Amazon.
Free limit: the free version shows a limited set of results per search; the full lists are part of Ahrefs' paid plans.
Best use: a quick difficulty check on promising keywords.
6. Semrush free account: best free competitor keyword research tool
Semrush lets you create a free account with access to its keyword and competitor tools, including seeing which keywords a competitor's domain ranks for.
Free limit: at the time of writing, around 10 requests per day, with a limited number of results per report.
Best use: free competitor keyword research. Enter a competitor's domain to see a sample of the keywords sending it traffic, then look for the gaps you could fill.
7. Ubersuggest: best all-in-one overview for beginners
Ubersuggest combines keyword ideas, volume, difficulty and a simple domain overview in a beginner-friendly interface.
Free limit: 3 searches or reports per day on a free account, with a shortened list of keyword suggestions.
Best use: occasional checks when you want volume, difficulty and ideas on one screen.
8. AnswerThePublic: best for question keywords
AnswerThePublic organizes search suggestions around question words (who, what, why, how), prepositions and comparisons, which is useful for blog posts and FAQ sections.
Free limit: 3 searches per day on the free plan.
Tip: NicheSpark's Questions method collects question-style suggestions from Google with no daily search limit, so the two work well together.
9. Moz Keyword Explorer: best for difficulty and SERP analysis
Moz's Keyword Explorer shows volume, difficulty, organic click-through rate and the current top-ranking pages for a keyword.
Free limit: 10 queries per month with a free Moz account.
Best use: a careful look at the handful of keywords you're most serious about.
The free keyword research stack we recommend
- Find ideas with NicheSpark: run A to Z, prefixes, suffixes and questions on your seed, and let it group the results.
- Size the best groups with Google Keyword Planner ranges or Ahrefs' free generator.
- Check difficulty on your top picks with Moz or Ubersuggest's daily free searches.
- Spy on competitors with Semrush's free account.
- Track what works in Google Search Console once your pages are live.
That combination covers discovery, volume, difficulty and competitors without a subscription. The trick is using each free plan for what it does best instead of burning your few daily searches on idea generation.
Free vs paid: when to upgrade
Free tools are enough to research a niche, plan a site and write your first dozens of articles. A paid tool starts paying for itself when you need exact volumes at scale, full competitor keyword lists, or daily rank tracking for many keywords. If you're just starting, spend your effort on research and content first and your money later.
Frequently asked questions
What is the best free keyword research tool?
It depends on the job. For long-tail ideas, NicheSpark collects real Google suggestions with no limits. For volume, Google Keyword Planner is free with a Google Ads account. For competitors, Semrush's free account is the most useful. Most people get the best results by combining two or three.
Is there a completely free keyword research tool with no limits?
Tools that show search volume all limit their free use, because that data is expensive to collect. NicheSpark, Google Search Console and Google Trends have no daily search limits, but none of them gives exact search volume for any keyword.
Is Google Keyword Planner really free?
Yes, but you need a Google Ads account, and without active ad spend you'll usually see volume ranges instead of exact numbers.
What's the best free competitor keyword research tool?
Semrush's free account lets you look at a competitor's ranking keywords within its daily request limit. Ubersuggest's free searches also include a basic domain overview.
Can I do keyword research without any tool?
Yes. Typing into Google and reading the autocomplete suggestions is the original free method. It's just slow, which is why we built NicheSpark to do it systematically. See the complete autocomplete guide.