There are quite a few free and paid A/B testing tools that you can take advantage of. I've listed some of my favorites as well as one really popular paid service for larger businesses. For smaller businesses I would still recommend the free options.
Make sure you read my article on how to successfully do an A/B test on your website before you begin.
My personal favorite: Thrive Optimize
I personally love Thrive Themes and their suite of WordPress plugins. They are perfect for conversion focused websites. In their arsenal of plugin they got Thrive Optimize which is a A/B testing tool that is super easy to use.
Thrive Themes has it own website builder called Thrive Architect that I'm pretty sure you must use in order to use Optimize. If you're using Elementor or WordPress's block editor you sadly cannot use this plugin.
You can set the amount of traffic you wish each page should get. Normally I just leave it at 50-50. You can also set the tool to automatically choose a winner and deploy that version.
The goal can be based on revenue, subscriptions or visits to another page, like a thank you page after filling out a form for example.
The tool is also capable of doing multivariant testing. That means you can have more than just an A-page and a B-page, you could run many more tests. Let's say you want to test 4 different colors on your CTA button. You can then set up 4 pages, all with a different color and run them simultaneously. Neat, huh?
The downside is that if you're heavily invested in another page builder for WordPress or you're not even suing WordPress, this one is not for you.
The best free tool: Google Optimize
Google Optimize is a free application from Google that allows website owners to conduct A/B tests, along with other experiments. It is created to be simple to use, with a user-friendly interface and step-by-step guidelines for establishing and executing trials.
In order to utilize Google Optimize, a Google Optimize snippet needs to be installed onto the website. This snippet is a small section of JavaScript which enables Google Optimize to keep track of experiments' performance and provide detailed reports on the outcomes.
You can create several versions of a page or component, and Google Optimize will display each variant to a randomly selected set of visitors.
Google Optimize will of course integrate well with Google Analytics.
Award winning paid tool: Optimizely
This award winning Digital Experience Platform (DXP) can do A/B testing as well as multivariant testing. It claims that organizations that uses Optimizely see on an average 297% increase in ROI.
I have however not used this tool, but it seems like a popular A/B testing tools for those who wish to take the step to a paid software.
Utilizing Optimizely A/B testing provides benchmarks for for businesses and empowers marketing divisions with the power they require to increase visits, product procurement, as well as a variety of other metrics.
Optimizely's A/B testing and experimentation capabilities are helpful in improving website and corporate performance, applying experimentation directly helps to maximize outcomes.
Pricing seems hard to find and you must request a quote from the sales team. Some sources state that the annual price for Optimizely is $63 700 which is a hefty price to pay. Is it worth it? Probably not if you're doing basic split testing.