How to A/B Test Klaviyo Emails to Lift a Low Click-Through Rate

If your click-through rate is sitting low and you cannot work out why, A/B testing Klaviyo emails is the fastest, least dramatic way to fix it. Not a rebrand. Not blowing up your whole strategy. Just a series of small, controlled tests that tell you what your subscribers actually respond to, starting with the one element most brands never touch: the button.

Here is the thing. A low click rate is rarely a “your emails are bad” problem. It is usually a “we have not tested our way to what this audience clicks” problem. Those are very different, and the second one is completely fixable.

How do you fix a low click-through rate in Klaviyo?

Quick answer: Fix a low click-through rate by A/B testing your Klaviyo emails one variable at a time. Start with your buttons (the copy, the shape and the colour), then test subject lines and layout. Give each test a real sample size, and pick the winner on clicks, not opens. Opens are unreliable now, so clicks are the metric that actually tells you what is working.

Why does click-through rate matter more than open rate now?

For years, open rate was the number everyone stared at. Then Apple Mail Privacy Protection (a privacy feature that automatically loads email images in the background, whether or not the person actually opened the email) arrived, and it quietly broke that number for good.

Because Apple pre-loads your images, Klaviyo often records an “open” for people who never laid eyes on your email. So your open rate looks inflated and healthy while telling you almost nothing true. Chasing it is like celebrating foot traffic in a shop where half the “visitors” are mannequins.

Click-through rate is the metric that survived. A click is a real, deliberate action. Someone read enough, cared enough and tapped. That is why click-through rate, the percentage of recipients who click a link in your email, is now the honest signal of whether your emails are working. If you want the fuller breakdown of what drives clicks in the first place, our guide on how to increase email click rates is the deeper read to pair with this one. This post is the method: how to A/B test your way there.

What should you A/B test first to lift a low click-through rate?

Your buttons. Every time. It is the single fastest lever you have, and it is the one most founders completely overlook.

A/B testing, if the term is new to you, just means sending two versions of the same email to two slices of your list, then letting the data pick the winner. It is not guesswork. It is a controlled experiment with your own subscribers as the judges.

The button is where you start because a click is a physical decision, and the button is the thing being clicked. There are more variables hiding in that little rectangle than you would think:

• Button copy. “Buy now” versus “Become your better self” versus “Show me”. A direct, transactional line and an aspirational one can pull wildly different click rates from the same audience.
• Button shape. A round, pill-shaped button versus a sharp square one. It sounds trivial. It is not. Shape changes how clickable something feels.
• Button colour. A berry pink button versus a deep purple one. Contrast against the rest of the email is often what earns the tap.
• How many buttons. Sometimes stripping an email back to one single call to action beats five competing ones. Sometimes a busy, product-heavy email genuinely needs several. You do not know until you test.

Best practice is one clear call to action per email, so test that first. Try the single-button version against your current layout before you go anywhere near a redesign. Often that one change alone lifts the number.

A quick heads-up if you work with us or any good agency on this. When you are mid-test, you will see your buttons change shape, colour and wording between sends. That is not inconsistency for the sake of it. That is the experiment running. If a version genuinely does not sit right with your brand, say so, but know the shifting is intentional and temporary while we find the winner.

How do you A/B test one variable at a time in Klaviyo?

This is where most people sabotage themselves. They get excited, change the button copy AND the colour AND the subject line all at once, the click rate moves, and now they have no idea which change did it. The test told them nothing.

Change one thing per test. That is the whole discipline.

Klaviyo has A/B testing built into both campaigns and flows, so you do not need extra tools. Here is the method that actually produces answers:

• Isolate a single variable. This test is button copy. That is it. Version A says “Buy now”, Version B says “Become your better self”. Everything else stays identical.
• Give it a real sample size. A test across 40 people is noise, not data. You need enough recipients for the result to mean something. On smaller lists that can mean letting a test run across a few sends before you trust it. Patience here saves you from acting on a fluke.
• Pick the winner on clicks, not opens. Set the winning metric to click-through rate. Remember, opens are unreliable now, so a version that “won” on opens can quietly be losing you money. Clicks are the truth.
• Log it, then test the next variable. Winner locked in? Good. Now that becomes your control, and you test the next single element (shape, then colour, then subject line) against it.

It is slow and it is unglamorous, and that is exactly why it works. Each test compounds on the last, and a few months in you are not guessing what your audience clicks. You know.

There is a lovely side effect to all of this, too. Every time someone clicks, you are gently training them to keep clicking. An engaged subscriber who taps this email is more likely to tap the next one, and the one after that. You are building a habit, and that habit is worth real revenue over a year.

What should you A/B test after the button?

Once your buttons are earning their keep, move up the email. The order that gets results looks like this:

• Subject lines. These will not lift clicks directly, but they get more of the right people in the door to click in the first place. Test one angle against another. Curiosity versus a plain benefit, a question versus a statement.
• Layout and structure. Where the button sits, how high the offer appears, how much copy comes before the first call to action. Putting the discount or the main link higher up is a classic click winner.
• Copy angle. The words leading into the button matter as much as the button itself. If your emails are landing flat, the writing may be the issue, and our advanced email copywriting tips for high-converting Klaviyo campaigns will help you sharpen the lines that lead people to click.

The principle never changes though. One variable, real sample size, winner picked on clicks. Whether you are testing a button or a whole layout, that discipline is what separates a real test from a hunch.

Not sure your Klaviyo account is even set up to test cleanly, or where your biggest click leak actually is? A Mini Klaviyo Audit is a 15-minute personalised video walkthrough of your account for $69, and it will show you exactly where to start before you burn a single send on the wrong test.

Can chasing signups actually hurt your click-through rate?

Yes, and this is the part almost nobody warns you about. You can do everything right on the testing side and still watch your click-through rate sink, because the problem is not your emails. It is who is on your list.

Here is how it happens. You run a signup campaign with a big, low-quality freebie or a “comment and I will send you the link” offer, and the signups pour in. Feels like a win. But a chunk of those people are low-intent. Some enter a fake or misspelled email address. Some never wanted your product, only the free thing.

Now you have a list full of addresses that do not open, do not click and, worse, bounce. Your bounce rate (the share of emails that cannot be delivered at all) climbs, and inbox providers like Gmail, Yahoo and Outlook start reading that as a signal that you are a low-quality sender. That hits your sender reputation, the score those providers use to decide whether you land in the inbox or the spam folder.

A junky free offer does not just fail to grow your list. It actively drags down every good subscriber you already have. Because once your reputation slips, even your engaged people start landing in spam and the promotions tab, and your click-through rate falls off a cliff through no fault of your emails.

So subscriber quality matters every bit as much as click optimisation. A smaller list of people who genuinely want to hear from you will out-click and out-earn a bloated list of freebie-hunters every single time. If you want an easy quality lever, offer something that requires people to actually engage, like a discount code they have to apply at checkout, rather than a no-strings freebie that attracts anyone with a pulse.

This is also why regularly cleaning out dead weight, the subscribers who have not engaged in months, protects your reputation instead of hurting it. And with inbox providers getting smarter about engagement every year, it is worth understanding what is coming. Our breakdown of Gmail’s Gemini update and what ecommerce brands need to know in 2026 covers where deliverability is heading.

Key takeaways

• Click-through rate is the metric that matters now. Apple Mail Privacy Protection broke open rates, so clicks are the only honest signal of what is working.
• Test your buttons first. Button copy, shape and colour are the fastest lever for lifting a low click rate, and the one most brands never touch.
• Change one variable at a time. Test copy, then shape, then colour, then subject lines and layout. Change several at once and the test tells you nothing.
• Give tests a real sample size and pick winners on clicks. Small tests are noise, and a version that wins on opens can be losing you money.
• Every click trains the next one. Engaged clickers keep clicking, which lifts both revenue and deliverability over time.
• Subscriber quality protects your click rate. A junky free offer inflates your list with low-intent subscribers, spikes your bounce rate and damages your sender reputation.