Ecommerce email design best practices for Shopify brands

What makes a good ecommerce email design?

Clarity. Litmus says it plainly: "Every email should have one goal." The design's job is to make that goal obvious within a second or two of scrolling.

The best proof I have is a launch email from a haircare brand. It made $31,059 from 395 orders in one send, and email went from 23% to 47% of the brand's revenue that month. Why it worked: a new product and one clear call to action. Nothing fancy. The design got out of the way.

How wide should an email be?

600px. Klaviyo recommends "designing your emails at a width of 600px for desktop clients" and says sticking with 600px helps emails built in Klaviyo display well on mobile.

Design for the phone first. Litmus says "44.7% of opens" happen on a mobile device or client. For most Shopify brands I'd treat the phone as the main screen and the desktop as the bonus.

For images, Klaviyo recommends files of 1MB or smaller, and full-width images between 600 and 1000px wide and under 2000px tall. Big files load slowly on a phone, and slow is the same as invisible.

Should I send all-image emails?

No. It's tempting, because a designer can build the whole email as one picture and it looks exactly right. But you pay for it three ways:

• Images off. Litmus notes that images aren't displayed for many subscribers because of client defaults or personal settings, and without alt text "the email simply appears blank."
• Spam filters. Klaviyo warns that emails made "solely of GIFs and images (or are very image-heavy) may trigger spam filters," and recommends "a combination of images and text." Klaviyo also passes on Email on Acid's guidance of at least 500 text characters per email.
• Accessibility and AI. Screen readers can't read text inside an image. Neither can the AI summaries some inboxes now show. I cover that in Apple Intelligence email summaries.

What I'd do: keep your hero image, but put the headline and offer in live text right under it. And add alt text to every image. Klaviyo's own help center says "Always add alt text to your images."

How do I design for dark mode?

Assume a good share of your readers see your email with the colors flipped. Litmus groups email clients into three types: no change, partial invert and full invert. It lists the Gmail app on iOS and several Outlook versions among the full inverters.

The fixes that matter most:

• Logos. A dark logo on a transparent background can disappear on a dark screen. Klaviyo suggests a light-colored shadow or outline around it.
• Text in images. Klaviyo says "use text wherever possible, rather than using images that contain text." Live text inverts cleanly. Text in an image doesn't.
• Pure black and white. Litmus suggests skipping pure white on pure black, which can strain eyes and gets inverted by some clients. Slightly off-white and off-black hold up better.

Then send a test to your own phone with dark mode on. It takes two minutes and catches most problems.

How big should fonts and buttons be?

Big enough for a thumb and a tired eye.

• Font size: Litmus recommends raising your minimum body size from 14 to 16 pixels on smaller screens.
• Contrast: the web accessibility standard (WCAG) asks for a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. Light gray text on white usually fails.
• Buttons: Apple's design guidelines list 44x44 points as the default control size on iPhone. Make your button at least that tall and give it room.

Build buttons in code, not as images. Litmus calls these "bulletproof buttons" because they "display in all email clients even when images are turned off." Klaviyo's button block does this for you. An image of a button doesn't.

How many buttons should one email have?

One main one. Litmus warns that "including a ton of links... can dilute your message," while also noting a single CTA can leave out some readers. My take: one goal, one primary button, repeated if the email is long. Product grids are fine when the email is a collection, but even then the reader should know what you most want them to do.

Before you hit send, click every link. A strength training gear brand's restock email hit a 0.40% click rate, double every other send, and made $0. Across the portfolio, about 20 sends showed real opens and revenue but zero clicks, which meant tracking was broken. Clicks with no sales, or sales with no clicks, means something broke. I go through the checklist in email clicks but no sales.

Why does Gmail cut off my email?

Because the code is too big. Litmus says "Gmail clips any message with a file size of over 102 kilobytes," and that the limit counts the code, not the images. When it clips, the reader sees "View entire message" and often never taps it. That can hide your footer, your unsubscribe link and your best product.

Long emails with lots of sections, copied-in code from other tools, and heavy template builders are the usual causes. Shorter emails fix it. So does not stacking every product you sell into one send.

How long should a promotional email be?

As long as it takes to make one point. The shorter the email, the more attention the button gets. If you have three things to say, that's probably three emails, which also gives you three chances to test what actually works.

When should I skip design altogether?

Sometimes the best design is none. A plain-text email from a real person can feel more personal, and it goes live in minutes. I compare the two in plain text vs HTML email, and the founder version of it is in founder emails.

Design should follow the words, not replace them. If the copy is weak, a prettier layout won't save it. Start with ecommerce email copywriting and the subject line, covered in email subject line best practices. If you're using Klaviyo's AI to draft layouts, my take on where it helps is in the Klaviyo Composer review.

What should I fix first?

Open your last campaign on your phone with dark mode on and images turned off. If you can't tell what the email is selling and where to tap, fix that first: live text for the offer, alt text on images, one coded button. Then click every link.

FAQ

WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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