The 13 best free keyword research tools for SEO

Written by Tiago Silva. Updated on 21, February 2024

Keyword research is the foundation of successful content production, and if you have a limited budget, this guide will help you find good tools while keeping expenses at the minimum.


What is keyword research?

Keyword research is the part of SEO where you analyze what people are typing into Google to find content, products and answers around the topic your site covers.

This will help make sure you create content people are looking for.

The free SEO keyword research tools in this guide will help you identify the keywords people are already using to find your site, and the keywords your competitors are targeting.

Putting these lists together will enable you to come up with a content strategy for new content and the optimization of existing pages on your site.

Are free keyword tools useful and good enough?

Paid keyword research tools are usually better than their free counterparts as they have more data.

However, there are a bunch of good quality free tools that you can use to grow organic search traffic to the website.

A particular example, which we look at first, is Google Search Console. This tool should be used regularly by every SEO.

Google Search Console

Google Search Console is the best free keyword research tool if you already have content on your website.

This tool can be used to keep an eye on organic search traffic, but you can use it to find many keyword ideas.

As you publish content on your website Google will rank it for a set of search queries. Some of these you may have targeted, some you may have not.

Finding these accidental keywords that you rank for will give you the opportunity to optimize and improve existing content, or add new pages to your site.

To find keyword ideas on Google Search Console go to the Performance report on the left sidebar, and filter by impression or clicks.

Google Search Console queries with lots of impressions and low clicks.

The best part is that Google Search Console shows first-party data, which is much better than most search volume estimations other keyword research tools display.

If you find Google Search Console data useful, give SEOTesting a try as we have pre configured reports that will save you a ton of time when working with Google Search Console.

Google Ads Keyword Planner

Google Ads Keyword Planner is a tool for advertisers who use Google Ads, but it is also a useful tool for SEOs. Keyword Planner is interestingly the primary data source for many free keyword tools.

To get keyword volumes, upload your list, select the countries and you’ll get the average monthly search and cost-per-click data.

Cost-per-click is useful to estimate the commercial intent of a keyword. Usually, a higher cost-per-click means higher commercial intent.

Google Keyword Planner search volume for UK and USA.

Another great part of Keyword Planner for keyword research is the keywords ideas report.

Start by entering keywords or product names and the countries you want to target.

Then Google Keyword Planner will do its magic and bring you a list of related words and their monthly searches.

Google Keyword Planner keyword ideas for tui heroes.

Refine the search by including or excluding keywords.

If you want more keyword ideas, add more keyword variations to Keyword Planner.

Doing this can get you 10 times more keyword ideas if you go from 1-2 word queries (head terms), to 3+ words (long tail keywords).

Google Ads Keyword Planner is totally free, you only need a Google Ads account.

Google Trends

Google Trends offers you a free way to spot trends and visually explore historical data.

While the historical graphs are interesting, and seasonal trends can help you with content planning, the useful part of Google Trends with regards keyword research is the related queries section.

Google Trends related queries report.

The related queries section will generally only display head search terms that get a decent amount of searches, but it is still useful for developing the hubs of topic clusters.

Google

Google itself is a fantastic tool for keyword research.

You should start by doing a regular web search in the Google search box to find keyword ideas with autocomplete.

     Using Google autocomplete to get keyword ideas.

As you type your seed keywords, Google will start suggesting phrases they know people usually search for.

Note these down as they appear, as they are great keyword ideas for new articles or new sections in existing pages.

You can work your way through the alphabet. In our example below, our head term is ‘apple recipe’. We can start with the letter ‘a’ to get the first auto-complete suggestions related to ‘apple pie’.

Google autocomplete for the apple recipe query.

Alternatively, you can use a wildcard operator in the middle of the query to get suggestions.

     Google autocomplete using the wildcard operator.

Using this technique with "best * for puppies" shows suggestions for best dog food for puppies, best treats for puppies, etc.

After getting autocomplete suggestions, it's worth going to the search results and checking the People Also Ask (PAA) section.

Google uses ‘People Also Ask’ to show questions from users related to the search query. These are all great keyword ideas.

Tip: Check the search intent of the query before you start writing a single word.

The search intent will tell you what type of content you need to rank.

     Google SERP for the query sneakers.

Looking at the SERP is also a way to know the competition and your ranking chances.;

When you have a new website and see Wikipedia, Healthline, or The New York Times at the top positions, your chances of outranking them are extremely low, and it’s probably a wise decision to go after other keywords.

Pro tip: use Google search operators to check how many websites are using the same keyword variation you want in their title with the allintitle operator.

At the bottom of Google search results page, you can also find ‘Related Searches’ keywords.

Google showing related keywords at the SERP's bottom.

These are keywords Google associates with your search query, and could be relevant to include in your content, or as a separate supporting article.

Keywords Everywhere

Keywords Everywhere is a browser extension for keyword research. This one is a personal favorite that I use for my daily to enrich my Google searches with search volume data and related searches.

Keywords Everywhere will display People Also Search For queries, related, trending, and long tail keywords directly on the search result pages.

     Keywords Everywhere populating the right side of the SERP with several widgets.

This is convenient as you can quickly type a keyword into Google to check the competition and get even more ideas from those widgets.

Pro tip: Use the copy button to quickly get the keywords onto your clipboard rather than trying to select them with your mouse cursor and doing ctrl+c.

Keywords Everywhere has a growing number of reports like competitor gap, analyze a page's keywords, and do bulk searches.

Keywords Everywhere extension features.

The free plan for Keywords Everywhere is generous, but upgrading gives a lot of value for little money.

I use it daily, and it only costs me $10 per year.

As well as enriching and surfacing keyword ideas directly in the search results, you can also use Keywords Everywhere to get keyword data on your competitors.

     Keywords Everywhere link to show how many keywords a URL is ranking for.

Hovering over a search result will show you how many queries Keywords Everywhere estimates the page ranks for - you can see these actual queries by clicking on the estimated number.

Keywords Everywhere sources data from Google Keyword Planner and Clickstream data to show monthly volume, cost-per-click, and estimate the ranking difficulty of keywords.

This browser extension works with the following platforms:

  • Major search engines: Google, Bing, DuckDuckGo, and Yahoo.
  • Google products: YouTube, Google Trends, Google Search Console, Google Analytics, and Keyword Planner.
  • E-commerce platforms: Amazon, eBay, and Etsy.
  • Social media platforms: Instagram and Pinterest.

Answer the Public

Answer The Public is a keyword research tool that uses autocomplete suggestions from search engines.

They will show results divided into the following groups:

  • Questions.
  • Prepositions.
  • Comparison.
  • Alphabetical.
  • Related.

For optimal results, Answer The Public recommends using 1 or 2 words as the seed keyword.

To get their famous keyword cloud you only need to enter the query, and select the country.

Answer The Public word cloud for 'tui heroes'.

This example shows the questions related to "Tui heroes".

In the graph, each branch separates suggestions using a different question word, and darker colors represent the most popular search terms.

You can also see these keywords on a list view and export the data into a CSV file.

Answer The Public keyword suggestions in a list view.

The Answer The Public free plan doesn’t have a fixed number of searches per person as it depends on the total number of searches their website gets.

QuestionDB

QuestionDB is a tool that sources data from forums like Reddit.

The tool is similar to Answer The Public, but their different data source means the list of keyword suggestions will potentially be very different.

QuestionsDB report for 'pokemon' showing keyword ideas, questions and related topics.

The Questions DB report shows questions and keywords ranked from most to least popular.

In my test I saw that words like “worth”, “best”, “value”, “money” or “buy” are associated with the query, telling me there's commercial interest.

Grab these suggestions to produce content that people are likely typing into Google as question/informational type searches.

Keyword Surfer

Keyword Surfer is a Chrome browser extension created by Surfer SEO.

     Keyword Surfer extension on Google SERP.

This extension shows organic search volume estimates directly on Google’s search results and is an alternative to Keywords Everywhere.

Keyword Surfer has search data for more than 70 countries. Including the USA, United Kingdom, Australia, France, and Germany.

You can also find keyword ideas related to the search term directly on the SERP widget that are easy to copy by clicking on "clipboard".

Keyword Surfer has cool features to explore the SERP page called Correlation charts.

These charts estimate how much traffic each page gets, how many words are on the page, and how many times it mentions the exact keyword.

Keyword Surfer showing estimated traffic for pages in the SERP.

Keyword Sheeter

Keyword Sheeter is another bulk keyword generator tool that gets its data from Google autocomplete.

Their UI looks clunky and simple, but outputs keyword ideas really fast.

     Keyword Sheeter generating keyword ideas from a seed.

An interesting aspect of keyword sheeter is that you can create positive and negative filters to show or hide suggestions.

I like to use filters to look for questions.

Keyword Sheeter filter to show only questions.

You can also buy Sheet coins to access keyword search volume and their other reports.

The following Keyword Sheeter reports require credits:

  • Search Volume CPC Bids.
  • Exact Keyword Results.
  • All In Title Results Checker.
  • Top 100 Serps.
  • Term Explorer Difficulty Report.
  • Full Sheet Report.
  • Full Backlink SERP Report.

Ahrefs keyword generator

Ahrefs is a great all-in-one SEO tool, but it comes at a premium price.

Fortunately, they have a free keyword generator that generates 100 keywords ideas and 50 questions from a single seed keyword.

This tool doesn't require sign up and you can use it for unlimited searches.

ahrefs keyword ideas for 'pokemon cards'.

They will show the search volume for every keyword but only display keyword SEO difficulty for the top 10.

ahrefs keyword generator also shows question suggestions.

Ahrefs has more than 20 billion keywords in their database, so it’s a great source for keyword ideas.

You can also use the ahrefs keyword generator to get YouTube, Bing and Amazon search volumes.

ahrefs free keyword generator has search volume for Amazon.

As you can see from the example above, ahrefs shows different search volumes for Amazon and Google searches, which is helpful for e-commerce.

Moz

Moz is another big player in the SEO industry that offers a free keyword research tool.

You must however sign up for an account, and you only have free 10 queries per month, but you'll have access to all the data they have for the keyword.

Moz dashboard overview for 'pokemon cards' keyword showing search volume, difficulty, and organic CTR.

Moz can show up to 1,000 keyword ideas and associated search volumes based on the initial query. So in theory, you can find up to 10,000 keyword ideas per month.

You can start the research process by looking at your competitors' domains to know their relevant keywords.

This is pretty useful for competitor analysis and knowing the search volume and keyword difficulty.

Moz site overview.

I also like that Moz saves the keyword data until you close the tab. This means you can freely switch between keyword suggestions and SERP analysis tabs without burning searches or opening many new tabs.

Keyworddit

Keyworddit is a Reddit keyword research tool with a spin. It’s great when you don't know much about a topic.

Start by typing a subreddit and the tool will output keyword ideas sorted by monthly search volume.

Big SEO subreddit keyword ideas.

The context link makes a Google search using the keyword and search operators to only show results from the chosen subreddit.

Google SERP to get more context on r/bigseo keyword ideas.

These results are good to find long tail keywords or as seed keywords to continue research on the topic.;

Keyworddit might struggle to find keywords if your target subreddit has less than 10,000 members.

Keyworddit sources the monthly search volumes from Grepwords.

Alsoasked

Alsoasked sources its data from Google’s People Also Ask (PAA) section to generate keyword ideas in a chart view similar to Answer The Public.

Alsoasked graph with question suggestions.

The tool pulls the keywords directly from Google PAA before creating a report, rather than sourcing the data from a database, and can generate up to 100 keyword suggestions at once.

The main advantage of Alsoasked is that they connect the questions by subtopics giving more context letting you know other questions associated with the seed keyword.

The query "Pokemon cards" quickly shows questions like:

  • How do l get my Pokemon cards graded?
  • Will Pokemon cards lose value?

These help me understand the search intent and its related keywords I might not be aware of.

Alsoasked allows data exporting in CSV and image format.