6 Best Free Keyword Research Tools for SEO

Keyword Research Tools

Last Updated on January 14, 2021.

What are the best free keyword research tools?

Keyword research tools are one of the most important tools in a blogger’s toolkit. They make keyword research easy and effective.

With keyword research tools, you can discover more keywords to target. You can see such metrics as search volume, keyword difficulty, and latent semantic keywords. You can also use keyword research tools to discover the intent behind the keywords and phrases people use to search Google and other search engines.

Keywords play a very important role in both on-page and off-page SEO because it’s a search engine ranking factor. SEOs also advise that you use your target keyword in the post title, include it in H2/H3 tags, metadata, and so on. Keywords tools make it easy to discover these keywords.

In this post, I’m going to reveal to you 6 free keyword research tools to help you with keyword research and SEO. Some of them are absolutely free and some are freemiums, with a limit to how many keywords you can research within a timeframe.

Let’s go.

Glossary of terms

Here’s a glossary of the terms I used in the post. Knowing them will help you understand the post.

  • Seed Keyword = your original keyword; the one you type in the tool
  • Latent Semantic Keywords (LSK) = relevant/similar keywords to your seed keyword
  • Keyword Difficulty (KD)/SEO Difficulty (SD) = how hard it is to rank for a keyword, usually between 0 – 100. The smaller the number the better.
  • Search Volume = how many times a keyword is searched in a month
  • SEO = search engine optimization/optimizer
  • CPC = cost per click. How much a single ad click will cost you

6 Best Free Keyword Research Tools for SEO

  • Google Keyword Planner
  • Ubersuggest
  • Twinword
  • Keyword Tool
  • Answer The Public
  • Spyfu

#1 – Google Keyword Planner

From the name, you can easily tell this tool is from Google. Although originally made for Adwords, you can use Google Keyword Planner for keyword research. You can use it to generate new keywords and content ideas. You can also use it to peek (and steal) the keywords your competitors rank for.

Google made this tool for advertisers to conduct keyword research strictly inside their Ad platform so that they can target the right keywords and search terms in their PPC search campaigns. And because the Google Ads platform is free to use, you can use this tool for keyword research even without the intention of running ads.

As with any Google product, you have to sign in to your Google account to use this tool.

Here’s how to use it.

Go to Keyword Planner.

You should be taken directly to the GKP page, but if you’re not, click “Tools and Settings” and then “Keyword Planner.” You should have a page like the one in the screenshot below.

Free Keyword Research Tools - Google Keyword Planner

Click “Discover new keywords.

Under Start with keywords, enter your seed keyword in the search bar and click on the “Get Results” button.

In this post, we’ll use “keto diet” as our seed keyword.

Here’s the result:

A whopping 667 keywords suggestions. Scroll down or use the arrow buttons to see more similar keywords suggested by the tool.

You can see the search volume for both our seed keyword and the suggested keywords. Keto diet is searched over a million times per month.

Competition” isn’t about the competition of the keywords in organic search results, but for paid campaigns. High means a lot of publishers are bidding for the keyword. Low means very few bids. Medium is in-between.

You can use the columns tab at the top right to include more metrics such as ad impression share, account status, and so on. Those are useful only if you want to run ads, so I just ignore them.

Try Google Keyword Planner

#2 – Ubersuggest

Ubersuggest is a freemium keyword research tool from Neil Patel. I like this tool because it provides more data than most other free keyword research tools.

It provides data about the keyword search volume, estimates keyword difficulty, shows top-ranking pages in Google and also offers more relevant keyword suggestions.

You can use the tool without creating an account, but you’re limited to only four searches per day.

It’s easy to use. Just enter your seed keyword and hit enter.

You get:

  • Search volume
  • Search difficulty
  • Paid difficulty
  • CPC

Using our example keyword, here’s the result:

Scroll down a bit to get “Keyword Ideas.”

Click “View All Keyword Ideas” to see the keywords mine.

Here it is:

When you click on any of the suggested keywords, Ubersuggest displays on the right the pages ranking for the keyword, an estimated number of visits the page gets, the number of backlinks and social shares as well as the domain score of the website. This data tells you how much work you need to do and how many links you need to get to rank for the keyword. We can clearly see that “keto diet” is very competitive.

You can copy the suggested keywords to your clipboard and paste in a text editor or download them in .csv format.

Try Ubersuggest

#3 – Twinword Ideas

Yet another great keyword research tool with a lot of data to work with.

When you enter your seed keyword, it estimates the monthly search volume and keyword difficulty and also provides relevant keywords.

You don’t need to create an account to use Twinword Ideas and it also doesn’t have limits to the number of times you can use it, but it does limit the number of keywords and data it reveals.

Go to the website and enter your seed keyword and click “Suggest.”

Alongside the keyword data, it estimates the relevance of the suggested keywords to your seed keyword. And when you click on any of the suggested keywords, it takes you to the search results page on Google to see the pages ranking for the keyword.

You can also use the dropdown panes in the menu on the left to filter the keywords based on popularity, intent, keyword pattern, competition, and so on.

Let’s filter our keyword keyword based on user intent.

If you run an affiliate site, you’d want the keywords with transactional intent.

So here’s Twinword Idea’s suggestions for “buy or do something

Personally, I’ll go for keywords with 1k+ searches and an SEO competition score of 30 and less. There’s a lot of them here.

Try Twinword Ideas

#4 – Keyword Tool

Keyword Tool touts itself as the best alternative to Google Keyword Planner and, in fact, other keyword research tools.

It uses Google Autocomplete to generate new keywords. This means it’ll give you the same keywords you’ll get from typing in the Google search bar (which, by the way, is pretty much what most keyword tools do). The advantage to using this tool, however, is that it gives you way more keywords than you can patiently wait for Google Autocomplete to bring up. If you use the paid plan, it’ll also give you the historical data of the keywords.

You don’t need an account to use the free version. Just enter your seed keyword in the search bar and hit enter.

Let’s try our example keyword keto diet and see what we’ve got.

491 keywords. So when you type keto diet in Google, Google will help you complete the search with the bolded words, but I’m not sure they can provide as many as 20 keywords let alone 491.

Click the little bar chart in front of your preferred keyword to get the historical data.

For the keyword keto diet plan, you can see that there’s been a 33% decrease in the search volume, from about 140k searches in January 2020 to 60k in November.

Try Keyword Tool

#5 – Answer The Public

This tool is different than other free keyword research tools mentioned in this post in that it generates questions based on your seed keyword, which is great for content creation. So I see it as more of a content creation tool. It’ll help you with FAQs to add to your post.

While it has paid plans, you can use the free version without limitations, and without creating an account, too.

Type your keyword in the search bar and hit enter.

While it shows a visual chart by default, I prefer this one it calls Data because of the classic display.


If you’re writing a post on keto diet, you may consider answering these question:

  • can keto diet cause diabetes
  • can keto diet cause ketoacidosis
  • can keto diet cause kidney stones
  • can keto diet cause hair loss
  • can keto diet cause constipation
Try Answer The Public

#6 – Spyfu

Spyfu is another free keyword tool you can use to up your SEO game. You can use it to discover keywords that have high search volume but less competition because your competition doesn’t know about them.

Like Ubersuggest, you can use Spyfu for keyword research and also competition analysis. While it has a free version you can use even without creating an account, it provides very little info.

It’s best to create an account to get more data.

In this post, I’ll use it to steal the keywords of a random blog.

Visit the website and enter your competition URL. I’ll use eatingwell.com — not a competitor, but…

Here’s what they know about the website.

Scroll down a bit or click “top keywords” in the menu on the left to discover the keywords this blog ranks for and their position in the SERPs.


Spyfu - Free Keyword Research Tools

Click “View all organic keywords” to do just that.

Which is the best free keyword research tool for SEO?

Ubersuggest and Twinword and that’s because they provide a lot of useful data.

You can use these two keyword tools to uncover new keywords and also narrow down to a certain intent. You can use Ubersuggest to see the top-ranking pages for different keywords without having to manually check Google, which is a great way to generate new content ideas.

While most SEO keyword research tools will suggest related keywords and their search volume, Twinword will compare the relevance of the suggested keywords with your seed keyword. This will help you determine which keywords to add to your post, even if it doesn’t have a huge monthly search volume.


Agreed—free keyword research tools aren’t the best due to the limitations that come with them, but they can get the job done, especially if you’re just starting out and don’t have the budget for paid tools.

If you work your way around these free keyword research tools, you can hack them to discover great keywords.

Like I said earlier, my favorites are Ubersuggest and Twinword. They’re the proper keyword research tools because of the amount of data they provide.

Ubersuggest will show you relevant keywords and also sites ranking atop the SERPs for your seed keyword. Twinword on the other hand shows the relevance of the suggested keywords to your seed keyword and you can also filter the suggested keywords based on intent – informational or transactional.

Got tips to help us take maximum advantage of these free keyword tools? Share your tips with us in the comments.

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