Conversion Rate Optimization: The Definitive Guide
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Conversion Rate Optimization: The Definitive Guide

This is a complete guide to conversion rate optimization (CRO).

In today’s guide you’ll learn:

  • How to run A/B tests
  • How to optimize landing pages
  • How to convert first-time visitors into customers
  • Dozens of CRO best practices

In short: if you want to get more leads, sales, and signups, you’ll love this new guide.

Conversion Rate Optimization: The Definitive Guide


Chapter 1: CRO Basics

CRO Basics

In this chapter I’ll cover conversion rate optimization fundamentals.

(Including what it is and why it’s important)

So if you’re just getting started with CRO, this chapter is for you.

Let’s jump right in.

What is Conversion Rate Optimization?

Conversion Rate Optimization (CRO) is the process of increasing the percentage of people who take a desired action on a website such as making a purchase, signing up for a newsletter, or downloading a file. This is done by identifying and eliminating any friction or obstacles that prevent people from completing the desired action.

As you might expect, a “conversion” is the specific action that you want visitors to take.

Do you run an Ecommerce site? Then a “conversion” is buying one of your products.

Are you a blogger? Then a “conversion” is signing up for your email newsletter.

Are you a SaaS founder? Then a “conversion” is signing up for a free trial.

What is Conversion Rate?

Your conversion rate is the percentage of people that visit a page and take a desired action.

You can calculate your conversion rate by dividing number that actually convert by the number of people that visit a page.

How to calculate conversion rate

For example, let’s say that you run a software product that helps people stick to their diet.

And 100 people visit your homepage every month.

If 10 of those people sign up for a free trial, that page’s conversion rate is 10%.

Conversion rate as a percentage

Why is Conversion Rate Optimization Important?

You might have heard the phrase: “It’s easier to double your conversions than double your traffic”.

And it’s 1000% true.

A simple tweak on a landing page can double or even 10x that page’s conversion rate.

That’s why the ROI of conversion rate optimization is off the charts.

I’m not going to bore you with a bunch of stats. I just want to highlight a few industry studies that prove CRO is worth the investment.

68.5% of companies in one survey said that they plan to make CRO a “higher” priority than last year.

Businesses are investing more in CRO

And it’s no secret why: only 22% of businesses are happy with their site’s conversion rate.

Most businesses are not satisfied with their conversion rate

When businesses DO decide to invest in CRO, it usually pays off. Venture Beat reports that the average ROI from a CRO tool is 223%.

The average ROI from a CRO tool is 223%

Why Conversion Rate Shouldn’t Be Your #1 Goal

I should point something out:

The term “Conversion Rate Optimization” is kind of misleading.

Yes, you want to increase your conversion rate. But it shouldn’t be your #1 goal.

Here’s why:

Let’s say that you run an Ecommerce site that sells iPhones. And your conversion rate is 5%.

Example conversion rate

Well, if you started selling your iPhones for 1 dollar, your conversion rate would probably increase to 100%!

Example conversion rate

Bottom line? Increasing your conversion rate is nice. But the ultimate goal of CRO is to increase the amount of revenue that your site generates. 9 times out of 10, these two goals align. But it’s an important distinction to make.

With that, it’s time to dive into chapter 2.

Chapter 2: How to Get Started With CRO

How to Get Started With CRO

This chapter is all about the critical first step of any CRO campaign: collecting data.

And let me be clear about something:

Most people skip this step. And they end up testing random stuff (like button colors).

Sure, you might get a slight bump in conversions with a button color change.

But if you want to get 2-10x conversion boosts, this initial research is KEY.

So without further ado, here’s how to CRUSH data collection for CRO.

Internal Goals and Benchmarks

Your first steps are to set up goals for your CRO campaign… and figure out where you’re at.

For example, let’s say that you run an Ecommerce site.

Your goal might be to boost overall site conversion rate by 10%. Or maybe you want to focus on improving a specific product page.

Either way, it’s important to set these high-level goals BEFORE you get into the weeds of Analytics and A/B testing.

Then, once you’ve set your goals, it’s time to jot down your current conversion rate (aka your benchmarks). That way, you can monitor whether or not your conversion rate improves… and by how much.

Dig Into Google Analytics

So now you know your site’s current conversion rate. You also have a specific goal.


Now it’s time to figure out WHY your pages aren’t converting as well as they should.

And the first place to look? Google Analytics. Analytics tells you exactly WHERE conversions are strongest (and weakest).

For example, cart abandonment is a huge problem for many Ecommerce sites. And Analytics can tell you where in the process people tend to drop off. That way, you know where to start testing.

Ecommerce Sales Funnel

Another example: a blog.

You can use Google Analytics to see which blog posts do the worst job converting readers into email subscribers.

Low conversion rate

Analytics can also help you see conversion rate differences between devices.

For example, you can see that my conversion rate from tablets is almost half of mobile phones and desktops.

Tablet stats

Which means I’d want to figure out why tablet users aren’t converting. It could be that my pages display weird on iPads. Or that my popup isn’t loading on tablets.

Either way, this kind of stuff is usually a quick win. And something that you can ONLY find using analytics.

Find Quantitative Data

Quantitative data is another goldmine that you can use to increase conversions.

First, you can fire up heatmap and user session software like HotJar and Crazy Egg.

HotJar / CrazyEgg

These tools show you how people interact with your pages. Which takes a lot of the guesswork out of answering: “Why does this page convert like crap?”.

For example, I have two “helpful resources” in my blog’s sidebar. And according to my heatmap data, the vast majority of people completely ignore them.

Heatmap data

So if I wanted to improve the conversion rate on my blog posts, I’d want to test different resources in the sidebar… or delete them altogether.

You can also use survey tools to poll users about why they landed on a certain page.

For example, HubSpot asks multiple choice questions to better understand what their visitors want to achieve.

HubSpot – Bot

Collect Qualitative Data

Quantitative data is nice and all.

But if you want to paint a full picture of why people don’t convert, you also need qualitative data.

You can grab this data using:

  • In-person or Skype interviews
  • In-depth surveys
  • On-site surveys
  • Chat logs and customer support tickets
  • User testing

So yeah, there are a million different ways to collect qualitative data for CRO.

That said, the exact approach isn’t as important as asking the right questions.

Specifically, you want to ask questions that help you figure out why people DO and DON’T convert.

For example, let’s say you run an SEO agency. You’d want to ask current clients and site visitors questions like:

  • “What’s the #1 reason that you want to hire an SEO agency?”
  • “What other SEO services have you looked at?”
  • “What kind of price range are you looking at?”
  • “What would make you say: ‘YES, this agency is right for me’?”

Then, you’d want to use these responses to inspire A/B tests.

Speaking of…

Chapter 3: How to Run A/B Tests

How to Run A/B Tests

In this chapter you’ll learn how to conduct A/B tests like a pro.

So if you’ve ever asked yourself:

“How do I get started with split testing?”

“What’s the best A/B testing software?”

“How do you actually perform an A/B test?”

This chapter has you covered.

Do You Have Enough Traffic?

If your site doesn’t get much traffic, A/B testing is pretty much impossible.


Because your tests won’t reach statistical significance.

(Most optimizers consider a result legit at 90-95% statistical significance)

Fortunately, you can easily find out if your site has enough traffic for A/B testing with Optimizely’s Sample Size calculator.


Just enter your page’s current conversion rate, the boost in conversion rate you want, and a statistical significance level.

Optimizely – Form

And the tool will let you know how many visitors you need to hit significance with your test.

Optimizely – Results

What To Split Test First

One of the biggest questions people have about split testing is:

“What do I test first?”

It’s a tough question to answer. After all: there are a million things that you can test on your site, from headlines to pricing to button copy.

That said, here are 3 ways to help you decide where to start with A/B testing:

1. High-Traffic Pages

This is simple math.

When you improve the conversion rate on a page that gets a lot of traffic, you’ll get A LOT more conversions.

For example, last year I decided to run a split test on the Backlinko homepage.

Compare homepages

Why did I start with the homepage?

It gets more traffic than any other page on my site.

2. Worst-Performing Pages

You can also start A/B testing on pages that have a super low conversion rate.


They have nowhere to go but up.

In fact, you can sometimes see a 5-10x improvement on low-converting page with a single A/B test.

3. Qualitative and Quantitative Data

The data you collected in the last chapter will come in handy here.

Here’s where you let the data inform your first test.

For example, let’s say your user testing data told you: “People have trouble finding the button to book a room”.

Well, your first test should be putting a “Book a Room” button front and center on your page.

Create a Hypothesis

Now that you’ve decided what to start testing, it’s time to create a hypothesis.

Why is this important?

Well, without a hypothesis, you end up testing random stuff without any rhyme or reason.

And a hypothesis helps you test stuff based on logic and data.

(Not gut feelings)

For example, last year I decided to test a scrollbox at Backlinko:


My hypothesis was that a scrollbox would improve newsletter signups without hurting conversions in other places (like exit intent popups).

And I made sure to jot down that hypothesis before I started the test:


How to Run an A/B Test

Here are two tips to help you run split tests:

First, start testing BIG changes.

One of the most common A/B testing rookie mistakes is testing tiny changes.

(Like button colors)

Instead, you want to start testing two VERY different versions of your pages. Then, refine the winning page with smaller changes over time.

For example, when I ran a test on the Backlinko homepage last year, I could have tested my button copy, logos, headline font size… and a thousand other minor tweaks.

Instead, I tested dramatically different versions of the page.

Specifically, my old homepage linked to my recent blog posts.

Backlinko – Old homepage

So I decided to test that original design against a version that offered a free case study in exchange for an email.

Backlinko case study

Sure enough, because I tested something big, I got a BIG boost:

Form submit boost

Second, you’ll need software.

There are dozens of A/B testing tools on the market, like:

I personally use Optimizely, but it ultimately depends on your budget and the features that matter most to you.

Collect Results and Scale

Your last step is to collect your results, analyze them, and learn.

Fortunately, most A/B testing software lets you know if your results have reached statistical significance:

PST – Form variation

Then, once you’ve found a winner, it’s time to jot a few things down. Specifically, answers to these questions:

  • Was our hypothesis correct?
  • What lesson did we learn that we can apply to future tests?
  • Based on these results, what should be tested next?

Chapter 4: Conversion-Focused Design

Conversion-Focused Design

As you probably know, site design isn’t just about looking pretty.

Instead, the goal of your site’s design is to get your visitors to convert.

And in this chapter you’ll learn how to maximize conversions with design.

Persuade With Image Captions

According to one of my all-time favorite copywriting books, Cashvertising, captions get read 2x more than non-headline copy.

Don’t waste that precious real estate with a boring description. Instead, write persuasive copy in your captions.

Here’s an example:

Persuade with image captions

Guide Users With Directional Cues

Directional cues guide users to a specific place on your page. For example, if you see an image of someone looking to the right, you’ll probably look there too. Or if you see an arrow, your eyes will probably follow where it leads.

Here’s a great example of directional cues in action:

Amelia – Homepage

See how the guy is looking up at the button? Subtle… yet super effective.

Turn Boring Forms Into Fill In The Blanks

Let’s face it: no one likes filling out forms. That is, unless you make them fun. One company found that replacing a typical boring form with a “Mad Lib”-style form boosted form completion rate by 25%-40%.

HuffDuffer – Form

Make CTAs Look Clearly Like Buttons (Instead of Text or Images)

When it comes to CTAs, traditional-looking buttons work best. That’s because people are used to clicking on buttons.

And if your CTA looks like a text link or an image, people won’t always know that they’re looking at a call-to-action. You guessed it: that means fewer people will click.

Show a Giant Phone Number for Mobile Visitors

If you run a business where calls = leads = revenue, try turning your tiny text phone number into a large, clickable number. A prominent phone number can also boost credibility and trust.

Here’s an example:

1-800 homecare – Button

Use Short Landing Pages for Small Commitments

For small initial commitments (like an email opt-in or lead gen form) try a super-short landing page.

For example, Pastel’s trial signup page is extremely short and (I can imagine) converts well for them:

Pastel – Signup page

Use a Progress Bar

Use a progress bar for multi-step funnels and form submissions. Why? A progress bar motivates people to finish what they started. Here’s an example from GoDaddy:

Purchase steps

Use an “Action Color” For Your CTAs

The last thing you want is for your button to blend in with the rest of your page.

Fortunately, you can easily get around this issue. How? Make your CTA contrast with the rest of your page. And BINGO… you have a CTA that instantly stands out.

For example, in a case study published at Hubspot, Performable saw a 21% lift in conversions when they switched to a high-contrast red button.

Reduce Options and Form Fills

Lots of options=anxiety.

In fact, cutting out just a single option can make a HUGE difference. Expedia boosted annual sales by $12 million dollars by removing a “Company Name” field from their signup process:

Expedia – Form

Bottom line? Destroy all unnecessary options on your site.

Chapter 5: How to Create High-Converting Landing Pages

How to Create High-Converting Landing Pages

When it comes to CRO, landing pages are HUGE.

That’s because your landing page exists for one reason: to get someone to convert into a lead or sale.

So if you can increase your landing page conversion rate by 10%, that’s 10% added directly to your bottom line.

And in this chapter you’ll learn a handful of actionable techniques that you can use to boost your landing page conversion rate.

Test Negative Words In Your Headline

Outbrain discovered that negative words in headlines like “never” and “worst” outperform positive words, like “always” and “best”… by 63%.

Positive .vs. Negative superlatives in titles

For example, a headline like “5 worst foods for losing belly fat” will grab more attention than “5 best foods for losing belly fat”.

Replace “Buy” or “Sign up” with Benefit-Oriented CTAs

The word “buy” reminds someone that they’re about to make a big commitment. Not good. So instead of “buy”, use CTAs that emphasize what they’ll GET.

Here’s an example from Unbounce:

Unbounce – Pricing

Instead of “Buy Plan”, they say “Start My Free 30-Day Trial”, which is much more benefit-oriented.

Use Action-Focused Copy

Copywriters have long known that this action-oriented copy is more persuasive than passive copy.

So instead of highlighting facts (“Our product helps people lose weight”), describe what will HAPPEN when someone uses your product (“Lose that stubborn belly fat”).

Show Expert Social Proof

Social proof isn’t all about having thousands of customers. You can also use social proof in the form of quotes from experts, logos of companies you’ve worked with, and awards you’ve won. In fact, expert social proof (“Our clients include Microsoft”) can be more powerful than sheer numbers (“We’ve served 876 clients”).

You may notice that I use this strategy here at Backlinko. I include logos of places I’ve been featured at the top of my homepage.

Backlinko – Logos

Use Information Gaps

When you get a little bit of information (but not the whole thing) you’ll do almost anything to close the gap.

Information gaps are especially powerful for email opt-ins and lead generation.

For example, let’s say you just wrote a weight loss ebook.

You could use copy like this to create an information gap: “Research shows that this seemingly ‘healthy’ food actually slows down your metabolism”.

I know I’m curious about what that food might be (and I made that example up ???? ).

Make Your Headlines SUPER Specific

It’s a fact: vague headlines don’t sell. Instead, you want your headline to be insanely specific about what your product or service does. Yes, you may turn some people away. But your target customers will eat it up.

For example, look at BonFire.

Bonfire – Headline

Instead of something lame like “The Next Generation of T-Shirts”, they go with the much more specific “The easy way to design and sell t-shirts online”.


Use Inline Validation

Inline validation=awesome. Ever spend 10-minutes to fill out a form, only to see a “You need to accept the terms of service” error message? #facepalm

Instead of showing people errors after they fill out and submit your form, inline validation gives people notes as they work. Here’s a real-life example:

Form validation

And there’s data to back this up: several case studies (including this one) found that inline validation significantly improves form completion rates.

Use No-Nonsense Headlines

The purpose of your headline isn’t to straight up sell. Instead, the #1 goal of your headline is to show people the benefit of using your product.

That’s why you want to use copy that highlights the #1 benefit people will get from your product or service. Here’s a great example:

Iventlist – Headline

Use Likes, Users, Followers or Customers as Social Proof

Whether we admit to it or not, social proof has a strong influence on what we do. In the world of CRO, you can use social proof in the form of Facebook likes, customers, total users, number of downloads… or anything else that shows off social proof.

Here’s an example:

Intercom – Partners

Like anything in CRO, social proof doesn’t work 100% of the time. So if you already have social proof on your landing pages, you might want test removing social proof from your landing pages (or try a different form of social proof).

Replace Jargon With Plain English

Your visitor shouldn’t need a PhD to understand your copy.

The fact is, jargon like this does NOT work: “We are an enterprise software company that focuses on providing customers with revenue-driven solutions throughout the sales cycle.” Huh?

Instead, use copy anyone can understand: “We’re a CRM that helps you get more sales.”

Replace Blocks of Text With Bullets

No one likes to read huge blocks of text (especially on a super long sales letter). Instead, break things up with bullet points.

Bullet lists in content

Show Your Price on Landing Pages

If your price is lower than average, don’t hide your price. Why?

Well, when you hide your product’s price, people think: “Where’s the price? This thing must be crazy expensive.”

In fact, Market Dialer found that including a price of “$75 per seat” doubled conversions.

Price – A/B test

Chapter 6: CRO for Ecommerce Sites

CRO for Ecommerce Sites

If you run an Ecommerce site, you already know that you can draw a straight line between conversions and revenue.

The question is:

How do you optimize your ecommerce site for conversions?

That’s exactly what this chapter is all about.

It’s a collection of CRO techniques specifically designed to turn ecommerce site browsers into buyers.

Use Price Anchoring

Want to make your products seem dirt cheap… without slashing prices? Try price anchoring.

Here’s how it works: When you show someone a certain price, they’re “anchored” to that price for a short time.

(That’s why infomercials show a bunch of higher prices before revealing the actual price).

Williams-Sonoma anchors like a boss. Most of the products on their category pages have a “Suggested Price” price anchor:

Williams Sonoma – Price

Add “Reassurance Copy” to Product and Checkout Pages

Reassurance Copy are little snippets of copy around your CTAs that make your customer feel more comfortable about their decision.

This can be free shipping, a money back guarantee, your privacy policy, social proof, or a key benefit. is the king of Reassurance Copy. They sprinkle them EVERYWHERE. I count five of them just in the above the fold area of this hotel listing page:

Show MULTIPLE High-Quality Product Images

You probably already know that product images can make or break your product page conversion rate.

So before you throw up a single hero shot, consider featuring 5-10 images of your product.

You can show images of the product from different angles.

You can also show your product in action.

For example, this product image of a Crock-Pot features a delicious stew cooking in the pot:


Clearly Mark Your Top Sellers

Marking a product as a “Top Seller” or “Popular” s a VERY strong form of social proof.

Here’s an example:

Casper – Popular

Want to take this to the next level? Personalize your best seller list by customer segments or purchase history.

For example, notes that certain rooms are ideal for certain types of travelers: – Travellers

Have an (Awesome) Site Search

Site search can make a HUGE difference in Ecommerce conversions. Why? Because you’re showing people exactly what they want to find!

Pro Tip: Pay attention to products that people search for the most. Then, make those sought-after products easier to find. For example, you can feature them on your home page or at the top of a category page.

Feature High-Revenue Products Above The Fold

If you want an EASY way to increase conversions, feature your most profitable products front and center in the above the fold area of your site. This rule applies to your homepage as well as product and category pages.

Collect Emails and Nurture

Yes, you want that visitor to buy right away.

But unless you’re Amazon, that’s probably not going to happen. So instead of trying to close right away, consider a popup that offers something for free (like a list of recipes or awesome newsletter).

Here’s an example:

Instant Pot - Newsletter

Then, drip your new lead valuable content and discounts. When they ARE ready to buy, you’ll be the first company that comes to mind.

Add Product Filters

If you have a category page with 1001 products on it, add a product filter. That way, people can easily see items that fit their style, size and budget.

Kilt ecommerce site Kilt Society saw a massive 76% increase in revenue when they added a simple product filter to their category pages:

Kilt Society

That means 76% more men wearing kilts. That’s a good thing, right?

Let Customers Checkout as a Guest

Yes, capturing emails is wonderful. But if you force would-be buyers to “register for an account”, you might be losing out on some serious revenue.

Yes, Amazon and other giants can get away with it

Amazon – Charts

…but if you run a mom and pop Ecommerce site, let users buy without creating an account. In fact, 26% of people say they won’t complete a purchase if they’re forced to register for an account.

Use Discount Popups

Consider offering your visitors a discount in exchange for their email address.

The best way to do that? An exit intent popup.

Exit offer

Use Interactive Product Images

Interactive images are as close as you can get to an in-store shopping experience on the web. Ecommerce Partners found that an interactive zoom boosted sales at an online shoe store by 51%.

Add Trust Symbols

Several industry studies (like this one) show that trust symbols (like association memberships, credit card logos and security icons) boost conversions… especially at checkout.

Checkout badges

Optimize for Mobile Buyers

If you haven’t optimized your Ecommerce site for mobile phones and tablets, you need to hop in your Delorean and leave 1998 in a hurry.

And for the record: “mobile optimized” doesn’t just mean that your site technically works on an iPhone. The entire experience needs to be flawless. Otherwise, people are going to head over to Amazon.

For example, ProFlowers increased their conversion rates by 20-30% when they made their site easier to use on mobile.

ProFlowers – Mobile

Make Product and Category Pages Load Lightning Fast

Amazon once reported that one second of load site delay can cost them over $1 billion in annual sales. Needless to say, they don’t let that happen ????

Fast Company

So whether you run your Ecommerce site on Shopify or BigCommerce, it’s important that your pages load pretty much instantly. If you’re ready to get started, here’s a helpful guide to improving ecommerce site pagespeed.

Hide Your Coupon Field

When you see a coupon field on a checkout page, what do you do? You go to Google and search for coupon codes!

And you might never end up going back to that checkout page. So removing (or hiding) the coupon field can really help with shopping cart abandonment.

Here’s an example:

Promo code

Show Why You’re Better

You don’t always need to woo potential customers with fancy copy.

Instead, directly compare your product with the competition. That way, people can quickly see why they should choose you over the rest.


Test Different Prices to Maximize Revenue

You can split test headlines and button colors till you’re blue in the face. And hey, you’ll sometimes see a lift on conversions.

But you can sometimes get a HUGE conversion boost by lowering or raising your prices.

Obviously, a lower price can boost conversion rate… but hurt profits. And a higher price can hurt your conversion rate… and increase profits.

So if you decide to use this approach it’s important to look past pure conversion rate numbers and focus on revenue.

Keep the Number of Items In Your Cart Visible

People on a shopping spree can lose track of what they put into their cart. You can easily sidestep this issue with a feature that shows people how many items they have in their shopping cart.

Here’s an example from Keurig:

Keurig – Cart

Chapter 7: How to Create Irresistible CTAs

How to Create Irresistible CTAs

There’s no other way to say it:

Your call-to-action can make or break your conversion rate.

Use the wrong CTA? Your visitor will say: “Nah. Maybe later”.

But when you use the CTA, you’ll find more users hitting that “buy” button.

So without further ado, here are simple (yet effective) strategies you can use to craft powerful call-to-actions.

Test First and Second Person Copy In Your CTAs

Several CRO case studies show that first person CTAs (“I want to try it!”) works well.

However, some people have seen a higher conversion rate with the second person (“Get your free quote”). Try both.

Add Urgency to Your CTA

Want an easy way to get more visitors to whip out their wallets? Add urgency to your call-to-actions.

Pro Tip: Use numbers to spark urgency. For example: “Order in the next 2 hours for delivery today” or “Only 7 left” works better than “Supplies are limited”.

For example, look at easyJet. They actually show you the number of people looking at the same route. This makes you think “I better book this flight before someone else does”:

EasyJet – People

Tap Into Loss Aversion

“Loss aversion” is a powerful psychological motivator.

In other words: “Stop losing customers” is more convincing than “Get more customers”.

And research shows that people are MUCH more motivated to avoid a loss than to gain something new.

Add Countdown Timers to Time-Sensitive Offers

A countdown timer is one of the best ways to dial up scarcity for time-sensitive products.

In this ConversionXL case study, Marcus Taylor saw a 332% increase in conversions by adding a countdown timer to one of his landing pages.

Countdown timer