The what, why, and how of WordPress A/B testing

9 min read
Shawn Pfunder

Editor's Note: This article on WordPress A/B testing was first published on October 20, 2014. It was updated on November 4, 2018.

WordPress A/B testing, or A/B split testing, is a way to test two different types of web pages at the same time. A/B testing is one of the easiest ways to figure out what's working and what might work better on your website.

Not sure if your "Click Here for More Information" call-to-action performs better than your "Call Us Now for a Quote" call-to-action? Split testing helps you find out. A percentage of your visitors will see your first call-to-action and another percentage will see the second one. After enough people visit and interact with your site, you go with the one that works better.

This is great for obvious reasons. If you're a small business owner, there's nothing better than knowing if your website is helping your business be more successful. If you're someone who makes websites for a living, there's nothing better than showing your client that the stuff you're making for them is helping them do what they love to do.

Like anything on the Internet, split testing can be really, really complicated and involve a lot of math or it can be really simple---especially if you're just getting started. For now, we're gonna keep things simple and show you how to accomplish this within WordPress.

Why you should consider using A/B testing

Why should you do it? Simple. Because people are unpredictable. If you're like me, I think I'm pretty smart when it comes to words and design and marketing stuff. I know what they want! They just don't know what they want! But, it doesn't always work that way.

For example, you might think that the easiest way for your customers to contact you is a phone call. That's the call to action on your home page. It's gigantic. It's bold text nested in a bright yellow box. You're getting hundreds of visitors to your website, sometimes thousands, but **no** phone calls. What gives?

A/B split testing is a simple way for you to experiment and see if something different will help. Maybe if you change the color of the box, you'll get phone calls? Maybe if you use a Web form for people to contact you? Maybe they need to learn a little more about you before they give you a call? Maybe the call to action leads them to examples of the cool stuff you've been doing?

A/B testing call to action examples

Split testing is a simple way to try out something new, measure the results, and get a good idea of what works and what doesn't work for people who visit your website.

How you perform A/B split testing

Split testing requires you to make some technical modifications to your website and how it shows up for customers. In general, the process looks something like this:

  1. Make sure you have a way to measure interactions on your website (I use Google Analytics™).
  2. Design a new Web page with the new element you want to test.
  3. Save it with a new, unique name on your Web server.
  4. Program your site to show one page to some visitors and another page to other visitors.
  5. Measure your results and update your pages as necessary.

Now, in this article, I'm not going to go into a lot of technical details about how to set up Google Analytics, develop a new Web page, or pull this off with JavaScript or DNS goodness. There are a number of ways to do it and it depends on what you (or your developer) used to make your website, how you're measuring traffic and visitors, and whether or not you decide to pay for an A/B split testing tool or put something together using your own code or something for free.

I will, however, point you in the right direction to get you started.

If you're itching to get started, first make sure you have a Google Analytics account hooked up and working. After that, read through this guide, open up your analytics account, and start your first experiment. Make sure you have an alternative home page already set up. You'll need that when you create your first A/B split test, or experiment, in Google Analytics. Again, start with something simple:

  • Change the color of your call to action.
  • Try a different call to action (call me, contact me, sign up now).
  • Switch up your headline.
  • Swap out the photo of your business with a photo of yourself.

If you're still a little freaked out about the technical work you need to do to make this happen, don't worry. There are multiple ways to set up A/B split testing.

Setting up WordPress A/B testing

Seeing that a ton of small businesses (and web designers) use WordPress for their websites, we thought we should talk a little about split testing with that in mind. You can, of course, create a custom field in WordPress and manually add A/B split-test code to your web page — if you're comfortable with JavaScript and Google Analytics. We're going to keep things simpler than that. There are some great WordPress plugins that can set up split-tests for you — no coding required. And the plugins we looked at produce some really pretty charts.

We don't know about you, but we love really pretty charts.

Here are three split-test plugins for WordPress you should definitely check out. There are a lot of other options, but these are a great place to start. Before you set them up, we recommend you have two different pages you want to test ready to go. It makes things a lot easier.

NOTE: Installing all of these plugins is a snap. You don't have to download them and then re-upload them to your hosting account. Log in to wp-admin (or have your web developer log in to wp-admin). Search for them and install them from the Plugins section.

Option 1: Nelio A/B Testing

Nelio A/B Testing. To use Nelio in WordPress you'll have to sign up for an account. If you're just getting started, the Basic plan works fine. It gets you A/B testing, heat-maps, unlimited experiments, reporting, and unlimited email support. Support can be helpful, you know, for when you decide to get really fancy and test all your article titles and the featured images on your blog. The Basic plan includes a 14-day free trial and it's $29 a month after that.

First impressions? This one is easy to set up; you don't have to code anything. That's great. To create tests and run reports, you stay inside WordPress. That's cool. But perhaps the most impressive part of Nelio is how easy they make it to split-test nearly everything on your website: posts, pages, titles, themes, and CSS tweaks. They also do a really great job explaining conversion actions and why those are so important for testing the success of your website.

The price is a little higher than other plugins we looked at, but Nelio knows what they're doing. The multiple split-test options plus their A/B Split Testing blog and information about conversion actions might be worth the price. At least you've got 14 days to find out, right?

Option 2: Simple Page Tester

Simple Page Tester. Simple Page Tester is the least expensive of the options we looked at, especially if you're primarily interested in visits to your website. It's free.  Forever. Thing is, total visits don't paint a full picture when testing pages on your website. You'll eventually want to see conversion metrics (how many people clicked on something, signed up for a newsletter, downloaded a coupon, bought something). You can get a premium version of Simple Page Tester for $59 that tracks conversions, but even without conversion tracking it's a great introduction to split testing.

First impressions? It's not as polished as the other tools we looked at, but it's dead-simple to implement and it feels right at home in WordPress. Earlier in this post, I mentioned you should get two different pages ready to go before you set up your split test. That's not the case with Simple Page Tester. Install and activate the plugin, go to a post/page that already exists, click Setup New Split Test, and you can duplicate an existing post from there. After that, all you have to do is make adjustments to your new page. Change the title. Add a picture. Shorten the post. Out of the three split-test apps we tried, this one was the fastest to set up.

Once your test is live, you can set how much traffic to send to the original post and how much to send to the variation. Once you've had a solid amount of visitors (Simple Page Tester will tell you when), you click Declare Winner to route all the traffic to the web page that works. Kinda cool.

What are you waiting for?

WordPress A/B testing doesn't have to be scary or even difficult. You can use one of the examples provided above or you can try one of the free A/B testing plugins available on It doesn't matter how you perform your testing. What matters is that you are actively working to improve the user experience and do everything you can to connect with your website visitors.