Last updated: November 19, 2020

Best CRO and A/B testing tools in 2021

Growth Marketing

If you’re looking for a lean CRO stack of tried and tested tools, you clicked on the right article.

I’ve broken it down into the very best of the best. So you can quickly and easily get started running experiments or level up your existing CRO game.

But before we get down to it, let me ask you… 

What do icebergs and CRO have in common?

The answer: More than you think.

You see, most people think CRO is about testing tools. Find the best one, and you’ll have godlike powers.

While that might be true for some, a/b testing tools are really just the tip of the iceberg. 

What people often don’t see are the tools below the surface. The ones that’ll make or break your experiments. And if wielded the right way, can deliver you massive wins.

On that note, let’s dig into the tools…


Research Tools

The biggest wins will always come from doing the best research – qualitative and quantitative – not guesswork. Just good ol’ fashioned research mixed with some pretty cool modern tech that’ll make our job a whole lot easier.

Quantitative tools give us the numbers and data to see what’s happening on our site. While qualitative tools help explain user behavior and why people do what they do.



Google Analytics for quantitative analysis

GA is the old dog that’s always learning new tricks. It’s been around forever, always getting better, and the free version has everything you need to uncover opportunities and diagnose problems on your website.

The data you pull from GA should be the building blocks to help you run better experiments and get the most out of testing.

While it’s easy to understand out of the box, there’s a whole suite of features that are pretty advanced and extremely useful for anyone wanting to optimize their site. Things like goal/event tracking, funnel flows, and advanced segmentation. 


Mixpanel for quantitative analysis

Mixpanel is great for tracking user behavior across platforms for SaaS and product companies. If you want to see every action someone could take within your funnel, from the first touch point with your site, to email, to app usage and more, then Mixpanel has the capabilities to tell you everything you’d ever need.

Having used it before, I can tell you it’s not as easy for marketing people. There’s quite a bit of technical set up that feels better suited to developers. But once that’s done, it’s a treasure trove of useful information.

It really is a full-feature tool, and with a lot more to offer than Google Analytics. Use ‘Funnels’ to see where people drop off. ’Flows’ to explore user paths. And ‘Signals’ to find correlations between user behavior. 



Hotjar qualitative analysis - CRO tool

Hotjar is one of my favorite research tools. It’s got almost everything a growing company needs to better understand visitor behavior. You’ve got heatmaps, scroll maps, session recordings, and exit-intent polling all in one easy-to-use tool.

The best workflow I’ve found is to look at heatmaps and scroll maps first. See what people are clicking on and what they’re not. Look at your CTA’s, how people are moving through your website, and how far they scroll. 

You’ll quickly find what content is important to your visitors and where you should focus your testing.

Next up is session recordings. Hotjar lets you filter recordings and saves you a whole lot of time. See videos of users exiting on specific pages, rage clicking UX elements, and much more. The ROI of time spent watching session recordings can be massive if you know what you’re looking for.

Exit-intent polls are really the icing on the Hotjar cake. A great feature that allows you to discover why people are abandoning specific pages. Not only that, you get to read copy written in the voice of your visitor, which is extremely valuable for overcoming objections and using in your own copy.

Hotjar is a fantastic tool to have in your research arsenal. I’d highly recommend it – there’s also a feature-packed free version too.

If you’re looking for another similar tool that offers a bit more detail and complexity when it comes to heatmaps, then Crazy Egg is worth a try as you can really drill down into the specifics. It’s got almost all the features of Hotjar and then some, but the UX isn’t as simple.


Mixpanel for quantitative analysis

A pretty cool platform for seeing how real users interact with your website and walkthrough their feelings as they do it. Feedback from end users can lead to testing breakthroughs and uncovering issues you never knew existed.

You can choose from a certain demographic or use your own audience for tests. Either way, you can get some great feedback and discover hidden opportunities.


Typeform as a qualitative analysis CRO Tool

One of the best ways to truly understand the motivations, objections, and reasons why people buy, is with surveys. And you can’t get any easier than Google Forms. Quick to set up, results go into a Google Sheet, and it’s free.

If you’re looking for a prettier option with a better user experience, then check out TypeForm. It allows you to add logic to your forms and do some pretty cool targeting.

But in the end, whichever tool you choose, all that matters is the responses you get from your audience. Post conversion surveys are great for discovering why people bought, their journey coming to you, and their objections – all stuff you can use in your own copy. 

Post conversion surveys are often skipped by businesses, but the results you’ll get if you ask the right questions can deliver big wins in your testing.


Mobile Monkey - CRO and AB testing tools

Chat transcript mining can be a great way of getting to know your customers. In fact, talking with customers directly can often reveal key insights into their mindset, objections, and even the specific words they use. Much like exit-intent polls and post-conversion surveys.

If you already have a chat tool, that’s great. Read through your transcripts, see what the common objections are, the words your customers are using, and what they expect of you. Data like this can help nail down your value proposition and product messaging.

If you don’t have a chat tool, check out MobileMonkey. It makes chat available across your website, SMS, Facebook messenger & Instagram. You can also create multi-channel surveys, get more responses, and reach more customers on the apps they already use.

Surveys done by messenger platforms feel more conversational, often getting better, more natural responses. Which is super valuable for writing your web copy.


Copytesting qualitative analysis CRO Tool

Built by CXL, this is a great tool for figuring out what people think of your web copy. Get insights into their reactions, what they feel is compelling or unclear, objections and more. 

We both know how powerful copy can be. So choosing the right words that move your audience to action, that feel relevant and connect with them on a personal level, can make all the difference.

Copytesting can help you get quick insights into the mind of your target audience and improve your copy in a big way. And while this tool can be a little expensive, for those who don’t have enough traffic to run a/b tests on their own copy, it’ll help you iterate and improve your messaging.


A/B Testing Tools

After the research is done and you’ve got some solid insights, then you’re ready to set up your tests and get running. The tools below all do similar stuff, but depending on your business size, what you need, and your goals, there’s a few different options to consider.

JustUno CRO and A/B testing tool

Want to a/b test your popups? This is the tool for you. Popups and lead capture can be the lifeblood of an Ecommerce business, especially if your email flows are set up the right way. So it makes sense to a/b test lead capture offers, design, and copy. And Justuno is packed with features to help you do just that. 

Honestly, there aren’t many tools that do a good job with design, optimization, and reporting. But this one checks all the boxes and then some. It’s a tool we love here at GrowthHit and it’s been responsible for some big wins.


Google Optimize CRO and AB testing tool

Google Optimize is a free a/b testing platform that seamlessly integrates with other Google tools like Adwords and Analytics, which is great for Ecommerce and revenue attribution. 

It is limited in the number of tests you can run at any given time. But depending on your level of traffic, 5 tests at any one time might be all you need. Any more than this and you’ll need to upgrade to the paid version, which can get pricey compared to other tools.

However the free tool is solid, allows you to run client-side A/B tests, and the integration with Google Analytics makes it extremely valuable for analyzing test data.

On that note, one thing with Google Optimize is that you will need to pull your results into another source to analyze and have a visual representation of your data. Google Optimize does do a good job already, but it could be better.

In the spirit of this article and keeping things lean, if you’re looking to quickly and reliably set up, run, and analyze experiments, use Google Optimize.


Optimizely CRO and AB testing tool


Optimizely is a big name in a/b testing tools and is better suited to larger enterprises with bigger budgets. The onboarding process requires a phone call with a rep and custom tailored packages can be pricey.

However, there’s a lot of features like personalization, server-side experiments, and cross-platform testing. Where if you’ve got the budget, the team, and the knowhow, Optimizely is a good choice for an advanced full-featured testing platform.


Convert CRO and AB testing tool

Convert is a great tool that has some of the more advanced features found in Optimizely but without the high price tag. You can run many tests at the same time and it integrates with other tools like Google Analytics.

It has everything you need to run and analyze test data, with none of the fluff and bloat that often comes with other platforms. It’s also a tool loved by many in the CRO industry. With great pricing, a robust platform, and a focus on privacy, it’s a great tool for businesses that want to move beyond Google Optimize’s 5 test limit.


VWO CRO and AB testing tool

VWO is another great testing platform similar to Convert, but with more analytics and extra research tools. If you’d like an all-in-one research, analytics, and testing tool platform, then VWO could be for you.

They have reasonable pricing and packages are often tailor made for you after a consultation. So it’s not as easy to sign up and get started with full features. But it does deliver a lot of value for the price.


The Lean A/B Testing Tools Stack

If you’re looking for a lean a/b testing stack that gets the CRO job done and seamlessly integrates with Google Analytics, then go with Google Optimize. It’s enterprise level, simple to use, and has everything you need to increase your conversion rates.

The last thing that’ll make your stack complete is adding research tools into the mix. We’re a big fan of Hatjar here at GrowthHit. Heatmaps, scroll maps, session recordings, and exit intent polls – everything you need to understand how people are interacting with your site and more.

CRO can be complex and there’s always another shiny new tool on the horizon. But if you stick to the tried and tested ones in this article, use them the right way – pulling insights from both quantitative and qualitative research – then you’re setting yourself up for success.

Isaac Wardle, Growth Marketer Wardle

Helped grow multiple brands across Europe and Asia-Pacific with paid ads, lead generation funnels, and backend revenue optimization. Specialist in growth strategy, CRO, and UX copywriting. Bio-hacker and natural health nerd.

The #1 Newsletter for Growth Marketers & CEOs

The best kept secrets in growth. Every Thursday you’ll get:

  • 3 must-read articles
  • 1 podcast episode
  • Sneak peek at our startup studio

    Join the 5,000+ subscribers
    This is more useful than my MBA program
    It helped me get a raise!
    It just makes me feel smarter.

    Learn How 17 High Growth Brands Get Customers to Say

    ...“Shut Up And Take my Money” (INCLUDES EXAMPLES)