VWO Logo
VWO Testing
A/B Testing

A/B Testing Solutions to Maximize Your Website Conversions

Create and A/B test different versions of your website and its elements to continuously discover the best-performing versions that improve your conversions.

Know More
Complies with:
VWO GDPR Ready Badge
VWO CCPA Ready Badge
VWO G2Crowd Leader Spring Badge
VWO BS 10012 Certification Badge
Follow us and stay on top of everything CRO
Related content:

Why Email A/B Testing Should Be Your First Step as a Marketer

10 Min Read

When you step foot in the enthralling world of CRO, we are inundated with a gracious sprinkling of terminologies – “Landing Page Optimization”, “A/A”, “A/B/N”, “Above The Fold”, “Below The Fold”, and so on so forth!

We seldom consider A/B testing our email marketing campaigns. Year after year, email marketing delivers the highest ROI across all acquisition channels. Therefore, it’s sensible to pay attention to addressing ways that can enhance your email marketing efforts that yield you even higher ROI. 

In this blog post, we will discuss how you can do so by incorporating A/B testing best practices, methodologies, and mental models.

bar graph highlighting the Return on Investment from email campaigns

Image Source: Capterra

What is email marketing?

Email marketing is a direct form of marketing that utilizes emails to promote a business. It’s a form of relationship marketing that most brands do to directly engage with their potential customers and inform and update them.

Why email marketing?

Email beats social when it comes to customer acquisition by 40x, according to a McKinsey report. Your prospect takes your brand more seriously over email communication as compared to when they engage on social. Yes, email is popular.

Now, let’s understand how the game of email marketing is going strong in the world driven by social media. A study by Exacttarget found that 91% of people use smartphones to check their email as compared to 75% of people who use their smartphones for social media. Not leveraging such a group for email marketing means missing out on a potential channel, which is extensively used across the globe.

As compared to other forms of marketing, email marketing is a very personalized form of marketing to reach out and engage with your target customers. It is cost-effective, and the associated ROIs are higher as compared with other forms of marketing, such as display ads and other traditional ways. 

Email marketing enables businesses to not only reach out to targeted masses at a rate of nearly nothing per customer but also to track the metrics easily. 

The typical metrics for a successful email marketing campaign are open and click-through rates. To maximize your open, click, and response rate, you need to design your campaigns carefully. 

You can do this by testing your designed campaigns to figure out what works best for you.

Blog Banner Email Ab Testing

Why should you A/B test emails?

A/B testing is a great tool to help improve your email marketing performance— but only if you know what you’re doing. 

Experimenting with your email campaigns would allow you to compare and contrast the elements that would gauge their impact on your subscribers’ reactions.

A/B testing can be done by forming a hypothesis and then formulating a test to see the results.

With A/B testing, you can:

  • Increase the open and click-through rates: 

The tool allows you to identify common factors and trends that can help increase open and click-through rates. For example, make your emails mobile-friendly, show relevant information in images, use a responsive email design that will allow it to all screen sizes. 

With high click-through rates, there are chances that your subscribers are clicking on your website and engaging with the call-to-action (CTA) buttons such as filling forms. You may identify how many open emails led to sales or leads. 

  • Get clarity about your target group’s expectations:

Your communication should be relevant to your target group’s interest. You need to know them well to understand their behavior, and hence, their expectations. Craft personalized emails by addressing them with their names. You can do so by creating targeted content for the segmented list and address their pain points with a solution by privately arriving in their mailbox. 

  • Save time and money:

A lot of money, energy, and time is spent on creating landing pages, forms, and sending emails to a broad audience.Through A/B testing, you can formulate the right recipe for a successful campaign by implementing incremental changes that, leading to statistically significant results. 

What elements should you A/B test in your emails?

A/B testing or split testing is the practice of showing two variants of the same web page to different segments of visitors at the same time and comparing which variant drives more conversions. Typically, the one that gives higher conversions is the winning variant, applying, which can help you optimize your site for better results.

You can A/B test the email campaigns by sending a portion of your list one version of an email and the other a different version while you watch for changes in your open rate, click-through rate, or other KPI. 

The elements that you can A/B test are:

1. Email subject line:

Test the subject line for its length, topic, personalization, and the kind of promotion you’re planning to run through the emails.

how to set up a/b testing of subject line for an email campaign
Image Source: Business2Community

2. Preheader:

Try and include a preheader, and test it against preheader subject lines you may hypothesize would help increase open rate. You can also try personalizing the preheaders by adding the first name of the email recipient.

3. Different time and days:

You must test different time zones as you may be catering to a global audience, which means that send time of an email will affect your open rate. 

Send emails on weekdays as people are most likely to check their emails on weekdays as compared to weekends. For example, if you always send your newsletter on Tuesdays, try sending it on Wednesday at the same time to see what happens.

Many studies have been done on the best days and times to send emails. Here’s a great display of open and click-through rates from GetResponse, analyzing 21 million US-based emails.

comparison of email campaign open rate across different days of the week
Comparing open rates across different days of the week
comparison of click rate for email campaigns across different days of the week
Comparing click rates across different days of the week
Data sourced from GetResponse

Also, testing periods of time to send a message on users abandoning the site would help you optimize the open and click-through rates, which eventually affect your sales.

4. Visuals:

Since our brain reacts better to visuals than text, you make your copy super engaging by incorporating compelling visuals.

an example of an email from House of Fraser containing Visuals
Image Source: House of Fraser

5. Personalization:

There is nothing like personalizing your email design as per the expectations of your prospects. You can only accomplish this through effective communication. Your audience actually listens to you when you address them by their names, greet them through the right channel, at the right moment, with the right message. They are most likely to engage with your content if they entrust you with the solutions to their pain points. 

an example of a personalized email from LinkedIn Learning inside the inbox
Image source: Biz Journals

6. Content:

Content is the king! Your content is the copy you write, images, videos, gifs, and their placement in a particular layout to make your email look engaging. 

Below are a few interesting parameters that you should test in your content:

  • Length: You must A/B test your copy for its length to understand and conclude if your audience prefers short-form copy with links or a long-form copy to delve deeper. 
  • Specific or generic: You don’t know what would work best for your target group, so it is recommended that you test your copies as specific and generic and see which one gets more traction. 
  • Positive, neutral, or provocative: By incorporating positivity in your copy, you are engaging with your reader’s brain in a powerful way that would result in a better understanding of your message. Your readers are more likely to convert if you engage them and motivate them through a robust and well-written copy.

7. CTA and buttons:

Your call to actions can be tested against copy and color.

  • Copy: By testing generic CTA’s such as “Buy more” against specific CTAs like “Get your custom denims here,” you might be able to understand which works wonders for your brand. 
  • Color: Your CTA button must complement the rest of your email body and stands out. For example, a CTA button in green on a white background is very impactful.

A/B testing best practices

Your email marketing solution should offer you A/B testing functionality. Still, even if it doesn’t, you can create your testing campaigns by manually segmenting lists and creating separate campaigns for each. 

Review the following best practices to improve your email A/B testing campaigns:

Tip #1: Start by formulating a hypothesis 

If you make changes to an email, run an A/B test, and find out that one variation performs better than another, that’s a start. But if you don’t know which elements to test, why do you feel the need to run a test, and what’s the goal you want to achieve, you can’t go ahead. 

So, start by formulating a hypothesis and define what you want to improve and why you think the changes will contribute positively to your desired outcome.

Tip #2: Test high-impact and low-effort elements

While A/B testing, make sure you do not get overwhelmed and start testing every element. You must try and test elements that you feel can pose a high impact on your email open rate. Work primarily on your CTAs, headlines, visual hierarchy, etc., that can be quickly executed in the test.

You can, later on, shift to testing the timing of your email automation flows–the actions you use as triggers, or the way you segment your recipients as well to gauge their impact on the open rates.

Tip #3: Focus on frequently sent emails first

Focus on the emails that you send frequently. For instance, your weekly newsletter emails. Pay much attention to the kind of templates you choose, the headlines you write, the type of content you wish to input, the placement of CTAs, etc. Testing and perfecting them helps you get more traction and leads.

Tip #4: Test broadcast, segmented, automated, and transactional messages

Test your broadcast and segmented messages and ensure you’re extending both the practice of A/B testing and noting any learnings you’ve discovered, to the other types of emails you send to the sample size.

Tip #5: Consider the potential impact of timing on email performance

No matter how excited you are to kick off a new email A/B testing program, be cautious if that means starting around a period of irregular seasonal or industry-specific activity. Reaching incorrect conclusions from abnormal spikes of activity won’t do your future testing any good.

Tip #6: Test one variable at a time and keep a log of your test

It is wise to keep one element at a time as you can precisely zero in on the change you made whose impact you are measuring though testing. Multivariate testing is an option if you want to test more than one variable. 

Also, do not forget to record your findings and learnings from every variable you tested, so that you can go back to analyze them and modify your campaigns.


From creating hypotheses to writing engaging crafty email messages that warrants a desired open rate, it is vital to A/B test every new change that you want to deploy in your email marketing campaigns. Also, do remember that increase in your conversion rate is a result of a combination of multiple marketing campaigns like retargeting via push notifications besides email. A mindful distribution of resources among these two tools can positively impact your bottom line and improve the overall conversions.

Banner Email Ab Testing
Nida Zehra
Nida Zehra As a marketing professional and storytelling enthusiast, I prioritize understanding data and insights over everything else while crafting a new story for experimentation. Besides work, you can find me reading fiction and, at times, metamorphosing into an artist through some discerning sorcery, which leads me to maintain an art and poetry blog on Instagram. Towards an innate linguistic inclination, I am currently looking forward to learning Persian to read and understand layers of the 14th-century Iranian poet Hafez's work—one of my most treasured literary possessions.
More from VWO on A/B Testing
A/B Testing Website Copy With GPT-3: Opening New Doors for Experimentation Using AI

A/B Testing Website Copy With GPT-3: Opening New Doors for Experimentation Using AI

From initially helping humans out with redundant and manual tasks, to now mastering creative jobs…

Read More
Shubhi Ahluwalia

Shubhi Ahluwalia

7 Min Read
Second Year In A Row: 9 Award Winning A/B and Multivariate Tests

Second Year In A Row: 9 Award Winning A/B and Multivariate Tests

WhichTestWon is a website that features results of A/B tests and multivariate tests wherein visitors…

Read More
Siddharth Deswal

Siddharth Deswal

2 Min Read
A/B Test Duration Calculator [Free Downloadable Excel]

A/B Test Duration Calculator [Free Downloadable Excel]

In a previous post, I provided a downloadable A/B testing significance calculator (in excel). In…

Read More
Paras Chopra

Paras Chopra

3 Min Read

Scale your A/B testing and experimentation with VWO.

Start Free Trial Request Demo
Invalid Email



All you Need to Know About Conversion Optimization Get the Guide