Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / How Email Preheader Text Doubles Your Open Rate
Transcript
- Lucas: We talk a lot about subject lines on this show. But there is another line of text that often does more heavy lifting than the subject itself, and most people leave it blank. Luna: You mean the preheader text? The little snippet that shows up next to or below the subject line in most inboxes? Lucas: Exactly. And according to a 2025 study from Litmus, sixty-eight percent of email clients display preheader text. Yet only about twelve percent of marketers actually customize it. The rest just let the email client grab the first few words from the body copy. Luna: Which is usually something like 'View this email in your browser' or the unsubscribe link. Total waste. Lucas: Total waste, and worse — it actively undermines your open rate. Because those default snippets are not selling the email. They are just instructions. So today I want to look at a specific B2B case study where a company rewrote their preheader text and saw open rates jump by forty-seven percent. Luna: Forty-seven percent just from a few words? That is massive. What kind of company? Lucas: It was a SaaS firm called ClientSync — they make CRM tools for small agencies. Their weekly newsletter had a decent subject line, but their preheader was the default 'Email not displaying correctly? Click here.' They ran an A-B test for four weeks with a revised preheader that summarized the value of the email. Luna: So instead of a technical instruction, they wrote something like 'This week: how to cut your onboarding time in half'? Lucas: Exactly that. In their case, the subject was 'Your Q2 pipeline checkup.' The control preheader was the default. The variant read: 'Plus a free template to score every deal.' That alone lifted open rates from twenty-one percent to thirty-one percent. And click-through rates went up twenty-two percent. Luna: Because the preheader completed the thought the subject line started. The subject teased the checkup, the preheader promised a specific takeaway. Lucas: Right. And that is really the core principle: the subject line and preheader should work as a two-line headline. The subject hooks you, the preheader gives you a reason to click. Let them be redundant or contradictory, and you lose the reader. Luna: I have seen brands use the preheader to add urgency, too. Like 'Ends tonight' or 'Last chance.' But does that work for B2B? Lucas: It can, but you have to be careful. In the ClientSync test, they tried a second variant with 'Only 48 hours left to claim your template.' That actually underperformed the value-based preheader by about eight percent on open rate. Their audience responded better to utility than to scarcity. Luna: So it is not one-size-fits-all. You need to know your list. Lucas: Exactly. And that brings up another point: mobile optimization. On iPhone Mail, the preheader shows up as a second line right after the subject. On Gmail web, it appears as a gray snippet. On Outlook, it is a single line. So your preheader needs to read well in all those contexts. Luna: Which means no cut-off mid-sentence. Litmus recommends keeping preheaders under one hundred characters, ideally around eighty-five. Lucas: Right. And if you are using a visual preview like Apple's list view, the preheader is the only text people see besides the subject. So it is essentially your second chance to earn that open. Yet most email builders treat it as an afterthought. Luna: I have also noticed some brands use the preheader to test a different offer than the subject. Like subject says 'New feature,' preheader says 'See it in action.' That way they appeal to different motivations. Lucas: That is a smart strategy. It is like running two hooks in parallel. But you have to make sure they don't contradict each other. If the subject and preheader tell two different stories, the reader gets confused and doesn't click. There is a fine line between complementary and conflicting. Luna: Let's talk about the technical side for a second. How do you actually set a custom preheader in most email platforms? I know Mailchimp and Klaviyo have a field for it. Lucas: Most platforms do. In Mailchimp, it is under the campaign settings — a field called 'Preview text.' In Klaviyo, it is in the email template under the 'Email preview' section. If you use custom HTML, you can add a hidden div with a specific class that email clients recognize. The key is that the preheader must appear before any other text in the HTML body. Otherwise the client will grab whatever comes first. Luna: And if you don't set it, the client takes the first visible text. Which is often your header image alt text or a navigation link. Lucas: Exactly. So even a simple preheader like 'Read this week's newsletter' is better than nothing. But the real lift comes when you treat it as a headline extension. The ClientSync case shows that a few words of specific value can double the impact of your subject line. Luna: I want to bring up another example. A fashion retailer I follow used the preheader to show a product benefit: 'This dress is machine washable.' Their subject was 'Your new summer wardrobe.' The preheader addressed a common objection. Their open rates went up, and conversions too. Lucas: That is brilliant. Objection handling in two words. So the preheader can do more than just tease content — it can overcome hesitation. In B2B, that might mean addressing time commitment: 'Takes three minutes to read.' Or social proof: 'Used by 500+ agencies.' Luna: Which brings up the question: should you A-B test preheaders the same way you test subject lines? Lucas: Absolutely. And the data says it is worth it. In a 2024 study by Campaign Monitor, brands that tested preheaders saw an average open rate improvement of fourteen percent. That is not as dramatic as the ClientSync case, but it is a consistent lift. And the cost of testing is essentially zero. Luna: So if someone is just starting out, what is your recommended first step? Don't overthink it? Lucas: Don't overthink it. Start by just changing the default text to something that summarizes the email's value. Then look at your mobile preview. If the preheader cuts off at an awkward spot, shorten it. Then test two variations: one value-based, one curiosity-based. See which resonates. Luna: And make sure the preheader is consistent with the email body. Nothing worse than a preheader promising a free template and then no template in the email. Lucas: That destroys trust. And it hurts your future open rates. So keep the promise. The preheader is a micro-commitment. Luna: If today was actually useful to you, the way these stay ad-free is listener support — buy me a coffee dot com slash fexingo. Lucas: Yeah, that really does help us keep going. And we appreciate it more than we can say. Luna: Alright, back to preheaders. One more tactic I want to mention: using the preheader to add a second call to action. Like subject says 'Webinar next week,' preheader says 'Register now – limited seats.' Lucas: That works especially well for event promotions. The subject informs, the preheader drives action. And because the preheader is right there, you are essentially doubling your real estate for the CTA without adding clutter. Luna: I have also seen brands use emojis in preheaders. Does that help? Lucas: It can, but it is risky. Some email clients strip emojis, or they render differently. In the ClientSync test, they tried a preheader with a checkmark emoji and it actually decreased open rates by three percent. So test it. But generally, plain text is safer and more universal. Luna: Good to know. So we have covered strategy, examples, technical setup, and testing. What is the one thing you want listeners to take away? Lucas: That the preheader is not optional anymore. It is a core part of your email copy. If you are not customizing it, you are leaving money on the table. Take five minutes before your next send and rewrite that default text. It could be the easiest open rate boost you ever get. Luna: And send us your results. We would love to hear if this works for you. Lucas: Absolutely. Next episode we are going to talk about another underrated element: the from name. How much does it really affect trust? Spoiler: a lot. Luna: Looking forward to it. Until then, keep those preheaders sharp.