5 Best Keyword Research Tools

Best Keyword research tools - hero image

Keyword research is at the center of SEO. 

It lets you find out:

  • what your customers are interested in,
  • what you are ranking for,
  • what you could be ranking for, and
  • how to expand your existing content. 

And keyword research is best done using tools that do most of the job for you.

Keyword research tools are a goldmine of information for SEOs, website owners, and content creators.

Knowing how important it is and how useful it can be, you want to be using the best tool available.

When researching this topic, all I could find were lists upon lists of different tools that didn’t really break anything down to help me choose the best keyword research tool.

That’s why I made sure this product showdown does more than present you with the 5 best keyword research tools on the market. You will be able to see exactly what is different between them. 

You will know what you get from expensive options and what you are compromising when buying a subscription for a cheaper tool or using a free competitor.

The criteria I explored include the ease of use, the number, and quality of options and functionalities, as well as the price. Here we go.


There’s barely a product showdown on the topic that doesn’t list Semrush in the top 3 positions. And for a good reason. 

Semrush started as a keyword research tool. Now, it’s a complete SEO tool suite.

Why is it our #1?

Semrush comes with a ton of high-quality keyword data.

It can inform you about the keyword volume, density (which may be important due to the properties of the TF*IDF algorithm), difficulty (and their recently updated keyword difficulty formula is very accurate – read their blog post to find out why), Ad CPC, and more. 

While there is a learning curve to using this tool, I think the User Interface is more intuitive than with other tools.

The search bar is a great example. You don’t have to find any specific tabs to perform a search. Type whatever you want, and Semrush will figure out what kind of data you are looking for, whether it be keyword analysis or a domain overview.

Top features

Keyword Overview: a quick snapshot of the most important metrics of a keyword.

Keyword Magic Tool: find both short- and long-tail keywords. The tool gives you comprehensive lists of relevant keywords related to your seed.

Phrase Match Report: type a subject you are interested in, and Semrush will provide variations of a keyword that are easier to rank for.

Keyword Analyzer: groups your targeted keywords into clusters to make planning out future posts and campaigns a breeze.

Trend Analysis: lets you know what the given keyword’s ranking was like over the last 12 months. This is very helpful when analyzing rankings over time and the impact of Google algorithm updates. Few other tools show this information.

Keyword Gap Analysis: instantly compares up to 5 domains to show which of your competitors’ keywords your site is not ranking for.

Keyword Gap analysis is one of Semrush's key features

Semrush is particularly useful when examining keyword gaps during competitor analysis. A wide range of filtering options makes observing changes between competitor rankings over time much easier. The size of its database is an added advantage that makes the research even better adapted to each case.

Semrush is praised for its competitor analysis. You can track specific URLs or even entire domains to see what queries and keywords they are ranking for.

The tool will even suggest who your competitors are. And this is not always that obvious. 

Semrush present search volume, keyword difficulty, and various other data points for each keyword

Pay-per-click data is within easy reach as other keyword analytics. You don’t have to perform separate searches. 

The tool can even inform you about yearly keyword trends, another great feature for planning future posts. More expensive packages let you track rankings from as early as 2012. 


Monthly search volume lets you know how many searches are performed on a given query per month. The trend column informs you about whether a query is becoming more or less popular. 

Tip: You don’t want to go for a dying keyword, but on the other hand, one that is growing will be harder and harder to rank for.

And lastly, any analysis you perform can be downloaded as a report in CSV and XLS formats. You don’t have to play around with excel at all: a huge time-saver. 

Semrush is the most comprehensive keyword and SEO tool out there. What comes with that is, unfortunately, the highest price. But, when you want the best of the best, you do have to pay for it.

Pricing options

There is a 7-day free trial that includes all the features. When it comes to plans, there are three types of subscriptions ranging from about $100/month up to roughly $450/month. You can up your plan anytime from the moment you sign up.

What you pay What you get
Pro: $99.95/month billed annually or $119.95/month billed monthly
  • keyword research, metrics, and tracking,
  • mobile rankings,
  • and more.
Guru: $229.95/month billed annually or $191.62/month billed monthly
  • all of the above,
  • historical data,
  • keyword cannibalization report,
  • page auditing,
  • and more.
Business: $449.95/month billed annually or $374.95/month billed monthly
  • all of the above,
  • product listing ads,
  • ability to import rankings from other tools,
  • and more.

Biggest selling point

Semrush has a convenient plugin that works with WordPress and Google docs. The SEO Writing Assistant analyzes your chosen target keyword and gives you real-time feedback. Some of the features it checks include:

  • SEO-friendliness,
  • Readability,
  • Originality,
  • Strong and weak points of text,
  • Tone.

And it’s actually free! All you have to do is create a Semrush account and you get one template to work with. If you need more, you will have to invest in a membership.

Pros and cons

Pros Cons
  • Most comprehensive toolkit
  • Constantly evolving
  • Biggest database of keywords
  • Flexible search bar
  • Wide range of metrics
  • Great competition analysis
  • Keyword volume is praised for accuracy
  • Reports in convenient formats
  • Relatively intuitive UI
  • Expensive
  • Learning curve
  • Data updates are irregular and hard to plan for

Ahrefs Keyword Explorer

Ahrefs is the other mogul in the SEO toolkit world. While it isn’t quite as praised as Semrush, the features it offers are many and of comparable accuracy. Ahrefs has its own database from which it pulls information. The tool is best known for its accurate and in-depth backlink analysis.

Why is it our #2?

Among other numerous features, Ahrefs can do all the basics like generate reports on keyword difficulty, suggested keywords, traffic, and more. 

Ahrefs keyword metrics

Like SEMrush, Ahrefs makes use of Clickstream data to determine the relationship between keyword volume and the number of clicks you can actually expect from ranking for it. This is incredibly useful; many keywords have huge traffic volume but don’t generate any clicks because of featured snippets and rich results.

The tool also allows you to track the featured snippets you have and suggests which you can possibly steal from competitors.

You can even search a particular domain to see how your competitor is targeting link-building and PPC. 

Ahrefs analyses the whole domain and shows referring domains and pages

You can also perform site audits to your own website to make sure no on-page issues are hurting your performance. The overview of your site will also let you know:

  • how many keywords you are ranking for (and what they are),
  • how many keywords you are tracking, and
  • your positions for those keywords.

In direct comparison with Semrush, Ahrefs is missing keyword data like the volume trend and number of results on SERPs. They both give the user search volume, CPC, and competition analysis. Ahrefs may arguably win the last point thanks to their in-depth backlink tracking.

A case study from 2020 shows that it provides more referring domains than Semrush. What’s more, for 2% of all the ones included in the study, Ahrefs was the only one to recognize the backlinks.

When further looking into these two top tools, many SEOs also mention the differences in data updates. Ahrefs does this regularly, so if you plan accordingly, you won’t end up with a fresh post or campaign plan that turns about to be out of date the next day.

Ahrefs outshines other tools with the sheer amount of data you can pull from it. My favorite tools within Ahrefs are the Content Gap Report with Keyword Explorer. Using these tools, you can expand your website structure and the keyword base your site is ranking for to a great level.

Let’s have a look at some of these notable Ahrefs features:

Rank Tracking: you can track keywords you are interested in with updates on their traffic by location and device. What’s more, Ahrefs can let you know what your progress against the competition is like for those particular keywords.

Content gap: search which keywords your competitors are ranking for that you are not (there’s even a checkbox to look up only top 10 Google SERPs)

Ahrefs lets you look up the content gap between you and your competitors

What I love about Ahrefs and Semrush are the Keyword GAP/Content gap features. Not sure which tool was the first to introduce this feature, but it’s absolutely nuts! You can easily see what keywords the competitors rank for, but you don’t. Mind the gap!

Organic keywords report: among other things, it lets you know which keywords you are already ranking for, but haven’t yet reached the top 3 positions. This is very helpful when you are trying to optimize an existing page. Those are the keywords you should be prioritizing.

Ahrefs shows you the parent topic for each keyword

I appreciate Ahrefs for the quick parent topic identification. When I am at the beginning of keyword research and not an expert in the field, this feature allows me to explore queries in a similar way as someone familiar with the subject. This saves time, makes topic exploration faster, and keyword research more relevant.

Tip: especially if you are performing keyword research outside of the US, look up which tool has the largest database for your target location before purchasing a membership.

Pricing options

There are four pricing plans and a 7-day free trial. The latter consists of all the Lite and Standard features for $7. If you choose to pay on an annual basis, you get 2 months free.

What you pay What you get
Lite: $99
  • 6 months of previous ranking and SERP position,
  • site audit,
  • mobile ranking,
  • site explorer,
  • and more
Standard: $179
  • all of the above,
  • extended features,
  • 24 months of previous ranking and SERP position,
  • tracking lost backlinks,
  • and more
Advanced: $399
  • all of the above,
  • extended features,
  • 3 users,
  • all historical ranking,
  • and more
Agency: $999
  • all of the above,
  • extended features,
  • 5 users,
  • and more

Biggest selling point

Ahrefs’ backlink analysis is second to none. It provides data as accurate as how many backlinks you need to rank on the first page of Google’s SERPs for a given query.

Pros and cons

Pros Cons
  • Comprehensive SEO toolkit
  • Great backlink tracking and analysis
  • Large keyword database
  • Wide range of metrics
  • Competition analysis
  • Dependable update schedule
  • Expensive
  • Learning curve
  • No volume trend data


KWFinder is dedicated to keyword research only. It has limited functionalities when it comes to in-depth competition analysis, gathering backlink data, and the like.

Why is it our #3?

Many SEOs find KWFinder results reasonably accurate. It is a simple tool that helps you find specific keywords and lets you know about their difficulty. 

There is practically no learning curve. While there are not a lot of functionalities, those it does have are easy to find and intuitive to use.

KWFinder shows keyword difficulty and search volume over time

There are filters for you to use to make the whole process more convenient and you can export lists to plan posts.

KWFinder shows you related keywords with their CPC, PPC, difficulty and more data points

KWFinder also keeps track of your searches and you can look through the last 20 or so. You can separate those into query types such as questions. It’s good quality for the price you pay.

What’s more, other than Semrush, no other tool provides data on the keyword trend.

Pricing options

There is a 10-day free trial that includes all features and a 48-hour money-back guarantee. There are three plans to choose from.

What you pay What you get
Basic: $29.99
  • 100 keyword searches
  • 200 keyword suggestions
  • 25 competitor keywords
  • 100 SERP lookups
  • 200 tracked keywords per day
  • 100,000 backlink rows per month
  • 20 site lookups
  • 1 user
Premium: $39.99
  • All of the above features extended 
Agency: $79.99
  • All of the above features further extended

Biggest selling point

The user interface is very intuitive and easy to navigate. If you are a beginner or work on a small scale, this tool is perfect for you.

Pros and cons


Pros Cons
  • Intuitive user interface, almost no learning curve
  • Relatively cheap
  • Trend analysis
  • Limited functionality

Google Keyword Planner

Google Keyword Planner is a so-called “big picture” tool. It wasn’t designed for keyword research and organic ranking. The goal was to make it easier for advertisers to target Adwords. Nonetheless, it can be a helpful tool for other things, especially that it is free.

Why is it our #4?

First of all, Google Keyword Planner is free. You do have to sign up for a Google Ads account, but there is no fee. You will have to provide some basic information about your business, and then you will be able to perform searches by keyword or domain.

Google Keyword Planner has a simple interface

This tool is integrated with Google Ads directly. This may mean abundant and fairly accurate data, but it is not a helpful tool if you are trying to rank on Bing or Yahoo.

The biggest advantages include the ease of finding long-tail keywords that are moderately easy to rank for.

Google Keyword Planner shows related keywords and their CPC

When it comes to analyzing competition, it is not as reliable as Semrush or Ahrefs, despite data coming directly from Google. This is because in 2016, GKP began grouping keyword variants together, so you are not getting as much information (or, rather, it is not as detailed). All in all, Google does care which keywords you choose to use.

You can also perform separate searches depending on the device you are targeting (mobile vs. desktop). But there is a catch; you have to set up a paid campaign.

Many SEOs like to take advantage of Google Keyword Planner in combination with other tools.

I appreciate Keyword Planner the most when performing bulk keyword analysis. There is an option to verify large portions of queries at once, therefore significantly speeding the process up.

Pricing options

Google Keyword Planner is free.

Biggest selling point

The most interesting feature is finding the top of the page bid range. It lets users know how much advertisers can make on a given keyword per click. 

Google Keyword Planner lets you find out the PPC bid range for keywords

Pros and cons

Pros Cons
  • Free
  • Data comes directly from Google
  • Lets you check bulk search volume for more phrases at a time than other tools
  • Only provides information for the Google search engine
  • Data isn’t meant for finding organic keywords, so it may be inaccurate
  • May be hard to navigate
  • Not a lot of functionality
  • Some features are only available once you set up a campaign


AnswerThePublic is a great place to start if you are an SEO beginner. The free version is limited, but you don’t even need to create an account. All data you pull from it is given to you in a clear, visual format. There is no clicking around thousands of tabs.

Why is it our #5?

Keyword research results are based on auto-complete features from Google and Bing. You can click on any query, and it will conveniently pop up in a new tab. This quickly shows you what kind of content is ranking for the particular keyword.

Answer The Public offers related keywords in a pleasing visual way

This keyword research tool is best for long-tail and question-based searches. The data is presented in a visual format.

I love AnswerThePublic for the human context it brings to keyword research. It shows what challenges users are facing, making it easier to plan content to respond to them. When you dive deeper and spend time with the tool, it allows you to squeeze out information on benchmarking and specific uses for products or services.

AnswerThePublic can also be a great fit if you want to build an FAQ section or target featured snippets.

You can sort the data in a variety of ways. The categories include:

  • Questions 
  • Prepositions
  • Comparisons
  • Alphabetical
  • Related
Answer The Public groups related keywords by prepositions

Pricing options

The free plan lets you search for 3 keywords per day. The Pro Plan gives you unlimited searches, and you can choose to be charged monthly or annually. There is also an Enterprise plan that gives you extended features.

What you pay What you get
$99 per month, charged monthly or $79 per month, charged annually
  • Unlimited searches and users
  • Ability to compare data over time
  • 5 Search Listening Alerts
  • CSV export function
  • Hide branches and suggestions functionality
  • High-resolution images
  • Priority customer support
$399 per month, charged annually
  • All of the above
  • 45 extra search listening alerts

Biggest selling point

Search Listening Alerts which let you know what new questions are asked on your chosen topics. You get updates every week. This feature is only available once you purchase a plan.

Pros and cons

Pros Cons
  • Great for long-tail and question-type keyword research
  • Free option
  • Lacks keyword volume
  • Results based on auto-complete features only
  • No historical research
  • Plans are expensive

Keyword research tools for a small budget

As mentioned above, Google Keyword Planner and AnswerThePublic are free resources that may be a good fit for some website owners or SEOs. If you do have an existing budget and need a bit more functionalities, KWFinder with a subscription under $30 may be a great answer.

Some other resources we can recommend if you don’t want to break your wallet include:

Soovle is one of the better free research tools that lets you optimize for Google, YouTube, Bing, Yahoo, and Amazon. A fun feature includes a “save suggestions” function. You simply drag and drop whatever you want to expand on in the future and you can conveniently download all of those in CSV format.

Google Search Console is also free and a great help when you want to optimize an existing page. The data comes directly from Google, so you can be sure it’s accurate, especially if that’s the search engine you want to optimize for.

 It mainly serves other purposes, but the Performance Report is pretty handy in giving you “opportunity keywords”. It lets you know which of your pages are bringing in most traffic from Google and the exact queries that made this happen. 

“Opportunity Keywords” are those that make your pages rank between the 8th and 10th position on Google. That means putting in a little effort gives you the possibility of getting those coveted top 3 positions in Google SERPs.

And finally, SECockpit has a subscription plan for $25 a month (at the time of writing this article). It works a lot like Semrush and Ahrefs, but it’s a little more limited in what it can do. Nonetheless, it can be overwhelming if you are just starting out. 

Quality of data

Why is data different across different keyword research tools? Well, they all use different methodologies. Not all are clear on what their sources are.

  • Any Google tools are obviously getting precise data from, well, Google. So you can rely on Google Keyword Planner and the Search Console to provide facts. Whether they give you all the facts is a different question.
  • Ahrefs have their own database. They have proprietary crawlers who collect the data daily. Their backlink index is updated every 15-30 minutes.
  • Semrush also use their own machine-learning algorithms to gather information, but they also quote “trusted data providers” as their source.
  • AnswerThePublic use auto-complete features from search engines and give the information to their users in a convenient format.
  • And finally, KWFinder have published a blog entry on where they get their data from, but… Well, it’s not exactly clear. In their own words, they use “multiple data providers alongside [their] own know-how and processing”.

Final thoughts

Should you invest in keyword research tools? Well, there are ways you can get around that. But it requires a lot more work and the data you find is likely going to be less accurate.

If you are just starting out, play around with free trials. See what you’re comfortable with. Before purchasing, make sure you are going to use all the tools you will be paying for. Don’t overpay for larger plans if you aren’t going to take full advantage of them.

And, remember, there is a learning curve to most tools. 

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