Applying email preview text best practices in Klaviyo for optimization is one of the fastest ways to improve your open rates. Preview text is the snippet of text that appears after or below the subject line in most email clients. Most brands treat it as an afterthought. The brands with the highest open rates treat it as a second subject line — because that is exactly what it is.
The rule: extend, do not repeat
Subject line: ‘The email mistake I see in almost every program.’ Bad preview text: ‘Read more inside.’ That adds nothing. Mediocre preview text: ‘Most brands are making this mistake.’ That says the same thing differently — still nothing new. Great preview text: ‘It takes two minutes to fix and it’s costing you opens every week.’ That adds urgency, adds specificity, adds a benefit — three new pieces of information in one sentence. The great preview text gives the reader two reasons to open instead of one.
Preview text formulas that work
The stakes extension
Subject line makes a claim — preview text adds what happens if they ignore it. ‘The metric that predicts email revenue’ + ‘Most brands have never calculated it and it shows in their numbers.’
The time and effort reduction
Subject line raises a topic — preview text makes it accessible. ‘How to build your abandoned cart sequence’ + ‘Three emails. Thirty minutes to set up. Runs forever once it is done.’
The specificity escalation
Subject line is broad — preview text narrows it to their situation. ‘What your open rate is not telling you’ + ‘Especially important if your Gmail open rates look lower than your overall numbers.’
The High-Performance Subject Line Library has 1150+ subject lines organized by intent that you can pair with optimized preview text — $17 at signifystudio.com/library.
Technical notes
Most email clients display 35 to 90 characters of preview text depending on device and screen size. Mobile clients show less. Write to 80 characters maximum and front-load the most important information. In Klaviyo, the preview text field is in the email settings before you enter the design editor — not inside the design itself. Set it intentionally for every email you send, including automated flows. Many brands set preview text on campaigns and ignore it entirely on flows, where every email runs indefinitely.
Need more tools and frameworks? Browse everything at signifystudio.com/library.
Want the rest of the system, not just this fix?
Run a free FlowScore audit to see what else your Klaviyo account is missing, or go deeper with the Email Psychology Mini Course ($47) or Email Mastery for Health & Wellness Brands ($297).
