Free Tools
8 min read

Best Keyword Research Tools for SEO

David Tatton
February 1, 2023

What you'll learn

What you'll need

What is Keyword Research?

Keyword research is a critical part of SEO (search engine optimization).

It’s the process of discovering search terms that users enter into search engines when looking for information online.

Keyword research allows you to develop a content strategy to create resourceful and helpful information on your website relevant to those keywords to help your business grow. 

The metrics associated with your keyword research are important when using keyword research tools, such as monthly search volume, keyword difficulty and competition, location-based search volume, search trends, and more.

So how important is keyword research for your online business?

Importance of Keyword Research for SEO

It is the imperative building block to your content marketing strategy that you can’t skip if you want to succeed online.

You won’t know what people are searching for, what your competition is ranking for, or what content to create on your website without doing keyword research.

You may find topics that your competitors have on their websites that get traffic and leads, but you haven’t covered that content. This creates a content gap that you can add to your keyword list to produce content.

It will also allow you to look into your products, industry, and what people are searching for in the different stages of your marketing funnel. Then you can provide a solution with your content that allows them to find you online, get into your funnel and start to build trust with your brand.

You need to make sure you target the most appropriate keywords related to your website when conducting your research.

But not every keyword you find should be one you go after. 

So what will help you to decide what keywords you should create content for?

Metrics are the key.

Metrics You Need to Know When Using Keyword Tools

Search Volumes

Keyword tools will give you an estimate of how many people are searching for that term on a monthly average. Most tools also let you see volumes in different countries, and some let you dive deeper into more target locations like a city or state. 

If a keyword doesn’t have that much search volume, then you won’t get that much traffic even if you rank well for that term. On the other hand, if a keyword has a ton of search volume, it may be a very competitive term and hard to rank, which is where keyword difficulty comes in.

Keyword Difficulty

Keyword tools give you some range of low, medium, and high difficulty, usually on a 0-100 scale. Difficulty can help you identify and prioritize keywords you should go after based on the competition of those keywords. 

Want some quick wins to get more traffic soon? 

Go after keywords with lower difficulty but decent search volume. 

Does your site already have good authority in your niche? 

Then go after keywords with higher search volume and medium to high difficulty levels.

Cost Per Click

If you plan to do pay-per-click advertising, you’ll want to know how much a keyword will cost you every time it gets clicked, known as cost-per-click (CPC). Services with higher revenues and buyer intent will have a higher cost per click, so factor this into your budgeting when doing your keyword research.

While metrics are important in creating data-driven decisions, always consider the intent of the keyword and look at what search results are coming up to make sure it’s a keyword you want to target.

Knowing these metrics should help get you started using the best keyword research tools for SEO. 

Best Keyword Research Tools for SEO

These are the top keyword research tools available, some paid and others free. But the paid versions will get you the data you need for your keyword research.


Ahrefs is considered one of the most popular search engine optimization tools available on the market.

It has been around since 2011 and is known as an all-around SEO tool for backlink analysis, keyword tracking, site audits. Ahrefs is known for very accurate keyword data, thanks to its clickstream data that pairs with Google Keyword Planner.

Ahrefs can also assist you in generating content ideas with Keyword Explorer and is presented in a very easy-to-read database. You can filter by any metric you wish, like volume or keyword difficulty, or even find questions people ask that surround your keyword, so you create resourceful content that answers those questions.

You can add any domain into their Site Explorer feature to see what organic keywords they are ranking for. This feature can help you start building your keyword list.

Similarly, their Content Gap feature allows you to compare your domain with up to 10 of your competitors and see what keywords they are ranking for that your site is not. You will find great keywords your competition ranks for that you can target with your content.

Ahrefs can also be used to find keyword data for different popular search engines, including Google, Amazon, Yahoo, YouTube, and Bing. 


Beginner-friendly interface

Keyword data from 10 different search engines

Has over 19 billion keywords on its database

Has a WordPress plugin that analyzes your content and backlinks

Backlink and content gap analysis

All-in-one SEO tool.

SEO alerts

Free Ahrefs academy training


Somewhat expensive for a small business

No free trial 

Learning curve but free training available

Top Ahrefs Features

1. Content gap analysis

2. Keyword explorer

3. Website SEO audit

4. Rank tracker

5. Content explorer

Ahrefs Pricing

The cost of Ahrefs starts at $82 per month when paid for a year upfront, or $99 per month if you want to test it out first. Large businesses that need higher limits and user seats can go as high as $832 per month when paid annually or $999 per month. Paying for the year upfront gives you a discount that gets you 2 free months. 

Unfortunately, there is no free trial so paying for it month to month is your closest option if you don’t want to invest for a year.

Visit Site


SEMRush is an excellent keyword research tool with a very large keyword database and competitive SEO analysis features that make it very easy to optimize your website. They are another favorite in the SEO industry and have been around since 2008.

Similar to Ahrefs, they allow you to input any domain to find keywords they are ranking for. You can also put in any keyword to get other long-tail keywords along with all of the metrics you need, like volume and keyword difficulty.

Their Keyword Magic Tool has a great interface that is very user-friendly, allowing you to filter, include, exclude and dig into specific keywords.

Another great feature that SEMRush has is its ability to set broad match, phrase match, or exact match that will help you find keywords broadly related to your topic that you wouldn’t have found by doing an exact match search.

Like Ahrefs, they also allow you to analyze your competition with their Keyword Gap feature, but it only allows you to compare up to 5 competitors at a time.

Once you have found some keywords you want to write content for, you can use their SEO Writing Assistant feature to optimize your content for the specific keywords you want to rank for, giving you a head start to higher rankings.

One drawback with SEMRush is that it only works with Google, but you can still get different locations and all the same metrics that other keyword tools provide, and more.


7-day free trial

One of the biggest keyword databases

All-in-one SEO tool 

Highly accurate keyword data

Established in the industry

Great customer support


Somewhat expensive

Keyword data only for Google

Top SEMRush Features

1. Keyword gaps

2. Keyword magic tool

3. Website SEO audit

4. Backlink analysis

5. SEO Writing Assistant

SEMRush Pricing

The cost of SEMrush starts at $99 per month when paying annually to $375 a month paid annually, which saves you up to 17% compared to paying monthly. Monthly pricing ranges from $119 to $449 per month. Unlike Ahrefs, they offer a free 7-day trial to explore the features that meet your needs.

Visit Site



Serpstat is a full suite SEO tool that is great for small businesses.  

It has an easy-to-use interface to navigate through data and has helpful customer support. Serpstat is an excellent keyword research tool with all the metrics like volume, CPC, keyword difficulty, and more that you need.

You’ll find a lot of features compared to other keyword tools like domain analysis, keyword research, PPC research, backlink analysis, and rank tracking.

One of their best features is their keyword clustering tool, which allows you to group similar keywords relevant to a particular topic. 

It is considered an excellent tool for beginners on a budget when comparing its price to others.


Full suite of SEO tools

More affordable

Rank tracking

Good user interface


Data not as accurate

No free trial

Some features are limited or locked on basic plans

Top Features of Serpstat

1. Keyword cluster tool

2. Keyword research

3. Pay-per-click research

4. API access

5. Rank tracking 

Serpstat Pricing

The cost of Serpstat starts at $55 to $399 per month when paid annually, saving you 20% on the year. Otherwise, it costs $69 to $499 when paying monthly.

Visit Site

Answer The Public

Answer The Public has a free plan with daily search limits that allows you to find long-tail keywords on a specific topic. 

Their pro plan removes your limit and allows unlimited searches, adding other features like monitor keyword alerts, new keyword suggestions, customization control, CSV exports, and more.

This tool will show what questions people ask online for each keyword you look for. What, when, where, will, why, who, which, can, and how to keywords are all shown in an organized web of keywords.

It also shows your keyword mixed with other relevant long tails used in search autocompletes for every letter in the alphabet.

Answer The Public will also produce a graph with many more long-tail variants with prepositions and more long-tail autocomplete search keywords in alphabetical order.

Unfortunately, it doesn’t give you any data about search volume, which is needed to make informed decisions.


Free plan

Long-tail keyword generator

Question keywords

Great for brainstorming

Keyword alerts

Trending keywords


Limitations on the free plan

No search volume data

Top Answer The Public Features

1. Long-tail keyword research

2. Question keywords

3. Alphabetical autocomplete keywords

4. Keyword alerts

5. New trending keyword suggestions

Answer the Public Pricing

They have a free plan with limitations, or their pro plan costs $79/month billed annually or $99 month to month.

Keywords Everywhere

Keywords Everywhere is a different long-tail keyword generator that works as a browser extension for Chrome and Firefox.

You’ll need to get an API key from their site and install the extension with the API key for their tool to work.

Their free version allows you to see related keywords, trend charts, YouTube insights, monthly estimated traffic, along with keyword density of content on the page for specific URLs.

The paid version uses a pay-as-you-go credit system that gives access to monthly search volume, CPC, competition, and trends data from the last 12 months.

This data will show up in your search results, allowing you to easily see data in an organized way while analyzing the top competitors.

The free version of Keywords Everywhere does not give you access to search volume data but is an easy tool to look up long-tail keywords.


Free browser extension

Pay as you go credits

Historical volume data from 2004

Keyword trends


Credits expire after 1 year

Not a dedicated all in one tool

Top Keywords Everywhere Features

1. Long-tail keyword research

2. Keyword trends

3. Historical volume data

4. Keyword density of URLs

5. Monthly traffic estimates of search results

Keywords Everywhere Pricing

You can purchase 100,000 credits for $10, 500,000 credits for $50, or 1,000,000 credits for $100 to get premium features. One credit allows you to see data for one keyword.

Google Keyword Planner

Google Keyword Planner is a great tool for PPC advertising since the data comes right from Google searches, and you can start building ad campaigns.

You can group keywords in ad groups and create negative keyword lists for PPC. It can give you a relatively accurate expectation for top-of-page bids to get an idea of what your cost per click could be.

What Google Keyword Planner can do that others can’t is get data for keywords at certain locations. Other keyword tools only allow you to get keyword data by country. With Google Keyword Planner, you can drill down to a state or city and get estimated search volumes for those areas.

However, the average monthly search volume data is set in ranges that don’t give you the accuracy of other tools with more precise search volume estimates.

Nonetheless, it still can give you plenty of long-tail and related keywords along with the competition level for those keywords. 

Pair the Google Keyword Planner with another Google tool, Google Trends, to get insights on volume trends from month to month over the years. 

For those that don’t mind the limitations compared to other keyword tools and not having all the features of competitive analysis and finding content gaps, this could be for you. If your budget for keyword research tools is free, this is for you.


Free with no limitations

Great for PPC campaigns

Location search volume data


Not an all in one tool

Features don’t compare to other keyword tools

Search volume ranges are less precise

Top Google Keyword Planner Features

1. Location search volume data

2. Keyword competition

3. Page bid ranges for PPC

4. Keyword plans

5. Long-tail keyword research

Google Keyword Planner Pricing

Google Ads Keyword Planner comes free because they know you are more likely to use their tool for PPC advertising. 


Keyword tools are essential for finding the right keywords to use in your content and target.

The data is out there, but you need to know how to use it to find the right keywords for your business to grow your traffic and build your authority.

You won’t know what content to create without keyword research to get more traffic to your site. With these keyword tools, you can analyze your top competitors, find gaps in your content, and make data-driven decisions with keyword research to build a content strategy that will increase your website’s rankings, traffic, and ultimately your revenue.

Try Chat by free: Whatever you need—just ask.
Start for free

Ready to level-up?

Write 10x faster, engage your audience, & never struggle with the blank page again.

Get Started for Free
No credit card required
2,000 free words per month
90+ content types to explore