Keyword research is the process of finding and analyzing the words and phrases that users type into search engines to see what they are looking for. Keyword research is essential for SEO (search engine optimization) because it helps to optimize web pages and content for relevant and high-demand keywords, which can improve their ranking and visibility on search engines. Keyword research tools are software or online applications that help to generate, analyze, and evaluate keywords for SEO purposes. Keyword research tools can provide various data and metrics on keywords, such as search volume, competition, difficulty, trends, cost-per-click, etc.

Keyword research tools can also help to find related, long-tail, question, and semantic keywords that can enhance the content quality and user intent.

There are many keyword research tools available in the market, both free and paid. Some of the best free keyword research tools are:

1. Moz Keyword Explorer:

Moz Keyword Explorer is a free keyword research tool from Moz, a leading SEO software company. Moz Keyword Explorer allows users to enter a seed keyword and get up to 1000 keyword suggestions, along with data on monthly search volume, difficulty, opportunity, and potential.

Moz Keyword Explorer also provides a SERP (search engine results page) analysis feature that shows the top-ranking pages for a given keyword, along with their domain authority, page authority, link metrics, and social shares. Users can also filter and sort the keywords by various criteria, such as relevance, broad or exact match, etc. Moz Keyword Explorer is free for up to 10 queries per month, and users can get more queries by signing up for a free Moz account or a paid Moz Pro subscription.

2. Google Keyword Planner:

Google Keyword Planner is a free keyword research tool from Google, the most popular search engine in the world. Google Keyword Planner is designed for Google Ads (formerly Google Adwords), which is Google’s online advertising platform. However, it can also be used for SEO purposes.

Google Keyword Planner allows users to enter a seed keyword or a website URL and get hundreds of keyword ideas, along with data on average monthly searches, competition level, and suggested bids.

Google Keyword Planner also provides a historical data feature that shows the monthly search trends and forecasts for a given keyword. Users can also filter and group the keywords by various criteria, such as location, language, device, etc. Google Keyword Planner is free to use, but users need to have a Google Ads account to access it.

3. Semrush:

Semrush is a comprehensive SEO tool that offers various features for keyword research, competitor analysis, site audit, content marketing, link building, etc. Semrush has a free version that allows users to perform up to 10 searches per day and get up to 10 results per search.

One of the main features of Semrush is its keyword overview tool that shows data on a given keyword’s search volume, difficulty, trend, CPC (cost-per-click), and SERP features (such as featured snippets, people also ask, etc.). Semrush also has other keyword research tools that show related keywords, phrase match keywords, question keywords, keyword difficulty comparison, keyword gap analysis (between competitors), etc. Users can also use Semrush’s domain overview tool to see the organic and paid keywords that any website ranks for.

4. Keywords Explorer by Ahrefs:

Keywords Explorer by Ahrefs is an SEO tool offered by Ahrefs. You can generate thousands of great keyword ideas, analyze their ranking difficulty and calculate their traffic potential.

5. QuestionDB:

QuestionDB is a free keyword research tool that focuses on finding question keywords that users ask on various online platforms, such as forums, and blogs.

6. Wordstream Free Keyword tool

WordStream is a company that offers online marketing software and services, including tools for keyword research, SEO, PPC, and social media. One of their free tools is the Free Keyword Tool, which helps you discover new keywords and performance data to use in your site content, Google Ads campaigns, and more.

The Free Keyword Tool by WordStream allows you to enter a keyword or website URL to get hundreds of relevant keyword results, tailored to your industry and location. You can also see accurate keyword volume and cost-per-click data, which can help you find the right keywords to target and optimize your marketing budget. Additionally, you can download your full keyword list so you can use it in your SEO content and search advertising campaigns.

The Free Keyword Tool by WordStream is different from other free keyword tools because it uses the latest Google search data to deliver targeted advertising ideas.

If you are looking for a free, fast, and easy way to find the best keywords for your website and online marketing campaigns, you might want to try the Free Keyword Tool by WordStream. You can access it from their website or from their blog, where they also provide more information and tips on how to use it effectively.

7. Wordtracker Free Keyword Research Tool

This is a tool that helps you find new and relevant keywords for your website and online marketing campaigns. It also shows you the search volume and competition data for each keyword, so you can choose the best ones to target.

The free keyword research tool from Wordtracker works by allowing you to enter a keyword or a website URL to get hundreds of keyword suggestions. You can also filter the results by industry, location, number of words, and more. You can download your keyword list as a CSV file or save it to your Wordtracker account.

Wordtracker claims that its tool is different from other free keyword tools because it uses the latest Google search data and its own proprietary search technology. They also have an extensive database of more than a trillion unique search queries, which means you can get more keywords, faster, than even paid keyword tools.

If you want to try the free keyword research tool from Wordtracker, you can access it from their website or from their blog, where they also provide more information and tips on how to use it effectively. You can also install their Chrome extension app, Wordtracker Scout, which lets you create a list of keywords from any webpage in one click.

8. Ubersuggest Free Keyword Research Tool

Ubersuggest is a free keyword research tool that helps you find new and relevant keywords for your website and online marketing campaigns. It also shows you the search volume and competition data for each keyword, so you can choose the best ones to target.

Ubersuggest works by allowing you to enter a keyword or a website URL to get hundreds of keyword suggestions. You can also filter the results by industry, location, number of words, and more. You can download your keyword list as a CSV file or save it to your Ubersuggest account.

Ubersuggest claims that its tool is different from other free keyword tools because it uses the latest Google search data and its own proprietary search technology.

If you want to try Ubersuggest, you can access it from their website or from their blog, where they also provide more information and tips on how to use it effectively. 

9. Similarweb Keyword Research Tool

The Keyword Research Tool by Similarweb allows you to enter a keyword or website URL to get hundreds of keyword suggestions, sourced from Google, Amazon, and YouTube. You can also filter the results by industry, location, number of words, and more. You can download your keyword list as a CSV file or save it to your Similarweb account.

The Keyword Research Tool by Similarweb also provides unique metrics and insights that can help you make better, data-backed decisions for your keyword strategy. Some of these metrics are Keyword Difficulty, Search Intent, Zero Clicks, and Trending Keywords. You can also compare keywords side by side and analyze the keyword gap between you and your competitors.

If you are looking for a comprehensive, accurate, and real-time keyword research tool, you might want to try the Keyword Research Tool by Similarweb. You can access it from their website or from their blog, where they also provide more information and tips on how to use it effectively. 

10. KW Finder Free Keyword Research and Analysis Tool

KWFinder is a keyword research tool that helps you find long-tail keywords, analyze SERPs, and dethrone your competition. It provides a ton of power for the price and is an excellent fit for niche site builders.

KWFinder works by allowing you to enter a keyword or a website URL to get hundreds of keyword suggestions, sourced from Google, Amazon, and YouTube. You can also filter the results by industry, location, number of words, and more. You can download your keyword list as a CSV file or save it to your KWFinder account.

KWFinder also provides unique metrics and insights that can help you make better, data-backed decisions for your keyword strategy. You can also compare keywords side by side and analyze the keyword gap between you and your competitors.

If you are looking for a comprehensive, accurate, and real-time keyword research tool, you might want to try KWFinder. You can access it from their website or from their blog, where they also provide more information and tips on how to use it effectively.