Best Keyword Research Tool: Semrush vs Ahrefs vs Moz Pro vs KWFinder vs Long Tail Pro vs SpyFu

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If you want a site that kills it against your competition, targeting the best keywords is a no-brainer. Keyword research can be a time-consuming chore unless you have a tool that simplifies the process while optimizing your results. Here, we give you the best keyword research tools, whether you’re a beginner or need to advance your SEO strategies.

Article Overview

Top 5 Features To Look For

Whether you’re doing basic keyword research for a blog or looking for specific keywords that are driving traffic to your competitors’ sites (and PPC, pay-per-click, conversions), there are several features to consider when deciding on the best keyword research software.

  1. Keyword suggestions: You want a tool that finds and suggests as many relevant keywords as possible.
  2. Search volume trend: The best tools show you search trends for each keyword.
  3. Filtering: You must be able to filter and organize large lists of keyword suggestions easily.
  4. Keyword difficulty: Keyword difficulty scores tell you how competitive keywords are. These scores can vary widely from one tool to another based on their data sets. It helps to know how experts and users weigh in on the accuracy of each tool’s keyword difficulty measurements.
  5. SERP analysis: SERP (Search Engine Results Page) analysis involves looking at the top web pages that rank for a specific keyword or topic. The best SEO software gives you tools to make sure your chosen keywords are relevant in your niche and determine if you can outrank your competitors.

Best Keyword Research Tools

We based our rankings on the strength of the features we highlight above and give you detailed information in our reviews.

Winner: Semrush Review

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Semrush, an all-in-one SEO software giant, has several different tools to help you conduct keyword research. With their Keyword Magic Tool, you can enter a seed word and get up to 2 million keyword suggestions. You can sort and filter these by search volume, keyword difficulty, SERP features, CPC (cost-per-click) data, and competitive density.

Using the Organic Research Tool, Semrush gives you the ability to see who is ranking for your desired keywords and then find out all of the other keywords that page is ranking for, allowing you to build out a robust content plan. PPC users can also see what keywords your competitors are bidding on. You can also see the exact search queries they’re ranking for, and you get a handy SERP overview. The one downside to Semrush is their Keyword Difficulty Tool. It’s not always as accurate as some other software, like Ahrefs.



  • Excellent competitor research — identify keywords that you might not be targeting now, but you should be
  • Database of 800+ million terms for keyword suggestions
  • Great sorting and filtering tools
  • Get long tail recommendations
  • Merge keywords to develop new word combinations
  • Easy tool to cross-match negative keywords
  • Keyword Difficulty tool places too much emphasis on total Google results, so it’s not as accurate as other software
  • Fee to add more than one user


Semrush offers a 7-day money back guarantee on all plans. The following prices are monthly. You can save up to 17% if you pay annually.

Pro Guru Business Enterprise
Price Per Month $129.95 $249.95 $499.95 Contact
Number of Users* 1 1 1 Contact
Results Per Report 10,000 30,000 50,000 Contact
Projects 5 15 40 Contact
Tracked Keywords 500 1,500 5,000 Contact

*Each plan gets one power user and additional users can be added for $20-50 per month.

Read Our In-Depth Semrush Review

Runner-Up: Ahrefs Review

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With its release of Keyword Explorer 3.0 in February 2019, Ahrefs now gives Semrush some serious competition as the best keyword research tool on the market. This totally revamped version is extremely user-friendly and gives you a ton of bang for your buck.

By analyzing large amounts of clickstream data, Ahrefs estimates keyword volumes from 10 different search engines. (Clickstream data includes data from a variety of sources other than Google, i.e., multiple search engines, mobile apps, various data mining tools, etc.).

Ahrefs lets you filter by keyword difficulty, search volume, number of words, SERP features and more. You can also get helpful SEO metrics, like return rate, clicks per search, % of clicks, % of paid clicks and more to help you optimize your SEO campaigns. Like Semrush, Ahrefs is another all-in-one SEO powerhouse software.



  • Keyword generator is powered by clickstream data and updates its database with fresh keywords every month
  • Database of 7+ billion terms for keyword suggestions
  • Identifies parent topics for each keyword to give you even more keyword ideas
  • Keyword difficulty score is among the most accurate you’ll find
  • Excellent SERP overview and position history features
  • No local keywords included in search volumes
  • Keyword suggestions don’t come with a relevancy score
  • PPC competitor research isn’t as strong as Semrush


Ahrefs offers a 7-day trial for $7 for its Lite and Standard plans. You can save 20% off the following prices if you pay annually.

Lite Standard Advanced Agency
Price Per Month $99 $199 $399 $999
Number of Users 1 1 3 5
Results Per Report 2,500 30,000 75,000 150,000
Projects 5 10 25 100
Tracked Keywords 750 2,000 5,000 10,000

3rd Place: Moz Keyword Explorer Review

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Moz has been a big player in the SEO game since 2004. Their Keyword Explorer uses clickstream data to generate suggested keywords and has solid keyword difficulty measurements. But this tool falls short compared to our top two picks. It caps keyword suggestions to 1,000 for each seed word search and often doesn’t give you search trend volume data.



  • Easy-to-use and visually appealing user interface
  • Uses clickstream data for keyword suggestions
  • Keyword difficulty score uses page and domain authority metrics for above-average accurate results
  • Caps keyword suggestions to 1,000 for each seed word
  • Doesn’t always give you search volume trend data
  • Lacks many filtering and sorting features you can find elsewhere
  • SERP analysis could be better


Moz Pro offers a 30-day free trial. You can also save 20% off the following monthly prices if you pay annually.

Standard Medium Large Premium
Price Per Month $99 $179 $299 $599
Tracked Sites 3 10 25 50
Tracked Keywords 300 1,500 3,000 4,500
Keyword Queries/Month 150 5,000 15,000 30,000
Keyword Lists 5 30 60 100

What About KWFinder, Long Tail Pro, And SpyFu?

KWFinder | Long Tail Pro | SpyFu

KWFinder Review

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Although not as powerful as our top picks, KWFinder by Mangools is a definite step up from free tools for keyword research — and many other SEO software options that cost a lot more. They also have a free keyword finder tool that includes 5 lookups per 24 hours and 50 suggestions per search.

Its keyword difficulty score is known as one of the most accurate in the industry. And it gives you metrics for each keyword, including search trends for the last 12 months, search volumes, and CPC and PPC data. The main downside with KWFinder is its strict search request and result limitations, which will keep heavy users away.



  • Easy-to-use interface
  • Great for finding low competition long tail keywords
  • Excellent keyword difficulty analysis
  • Good data filtering features
  • Ability to narrow research down to a local level
  • Strict caps on both keyword lookups and suggestions with every plan
  • Not ideal for competitor research
  • Separate SEO tools in their suite don’t sync together as well as Semrush and Ahrefs


Pricing plans give you access to Mangools’ suite of SEO tools, including keyword research and tracking, SERP analysis, backlink analysis and auditing. You can save up to 40% if you prepay for a year.

Free Basic Premium Agency
Price Per Month Free $49 $69 $129
Number of Lookups Per 24 Hours 5 100 500 1,200
Number of Keyword Suggestions Per Search 50 200 700 700

Long Tail Pro Review

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As its name suggests, Long Tail Pro is a great tool to find less competitive long tail keywords. It pulls keywords from Google’s Keyword Planner and uses a unique Keyword Competitiveness algorithm to calculate each keyword’s ranking potential (on a 1-100 scale).

You can conduct a website competitive analysis of the top sites using your chosen keywords and also enter a competitor’s domain to get their metrics and see your chances of outranking them. Its new Rank Value tool gives you an estimated monetary value, including income from AdWords and Amazon Affiliates, of ranking in the #1 spot for any given keyword.



  • Among the most accurate keyword ranking tools to help calculate keyword profitability 
  • Detailed competitor metrics
  • Get custom keyword difficulty recommendations
  • Fast, cloud-based platform
  • Can only get up to 400 suggestions with each seed word search
  • Some users report that the tool is inconsistent in bringing back data, i.e., the keyword analysis feature shows the load box but with no data


Long Tail Pro offers a 10-day money back guarantee and save 30% if you pay annually.

Starter Pro Agency
Price Per Month $37 $67 $147
Simultaneous Users 1 3 5
Daily Keyword Lookups 800 2,500 6,000
Tracked Keywords 30 200 1,000

SpyFu Review

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SpyFu’s focus is on competitive research for SEO and PPC. You can find out what your competitors are doing by seeing which keywords they buy, which ads they run, and which organic keywords they rank for. What stands out? Not only do you see this competitive information now, but there’s a 12-year history provided. SpyFu offers good keyword tracking on Google, Yahoo, and Bing.



  • Researching your competitors’ historic ads gives you an excellent opportunity to tweak your site’s ad copy
  • In-depth PPC and SEO SERP analysis
  • Can sort by search volume, cost/click, clicks/day, global or local
  • Steep learning curve for beginners
  • Seed keyword generation isn’t as strong as top tools


All SpyFu plans come with a 30-day money back guarantee.

Basic Professional Team
Price Per Month $39 $79 $299
Weekly Tracked Keyword Rankings 5,000 15,000 40,000
Sales Leads & Domain Contacts 250 500 2,000
Historical Data 6 months 10+ years 10+ years
API Access Checkmark Checkmark
Custom Brand Reports Checkmark Checkmark

What Are The Best Free Keyword Research Tools?

Keyword research is like everything else — you get what you pay for. That’s not to say some of the best free keyword research tools aren’t worth it for beginners or to supplement your main SEO tools. They just won’t meet advanced SEO needs. The following free tools come highly recommended by experts as great starting places.

Need Some Expert Keyword Research Tips?

Check out this brief video by SEO guru Neil Patel (who acquired and now runs the Ubersuggest tool we mention above) for some fantastic tips on how to do keyword research.

Find The Best SEO Tool For Your Business

Part of finding ideal keywords is analyzing how targeted keywords are trending. Learn more about how keyword trend analysis can help you get the best results. If you’re looking for more than keyword research in your SEO tool or need additional tools to cover all your bases, be sure to read our comprehensive reviews of the best SEO tools on the market. We include features, pros and cons, pricing and more for the most popular SEO tools you can find.

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The information provided through this website should not be used to diagnose or treat a health problem or disease; it is not intended to offer any legal opinion or advice or a substitute for professional safety advice or professional care. Please consult your health care provider, attorney, or product manual for professional advice. Products and services reviewed are provided by third parties; we are not responsible in any way for them, nor do we guarantee their functionality, utility, safety, or reliability. Our content is for educational purposes only.

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