Plain text vs HTML email: when to use each for an ecommerce brand

Plain text vs HTML email: what's the actual difference?

A designed HTML email is what most brands send: a header, product images, buttons, colors, a footer. It looks like a mini web page.

A plain-text email looks like something a person typed. Mostly words, a link or a simple button, very little design. In Klaviyo it's called a text-only email, and Klaviyo describes it as "generally much simpler in style and structure than HTML emails."

One thing that trips founders up: every HTML email built in Klaviyo's drag-and-drop editor already has a plain-text version that Klaviyo generates automatically, because not every inbox accepts HTML. That's a backup copy, not a strategy. This post is about choosing which style to send on purpose.

Which performs better, plain text or HTML?

In my own tests, it's been close to a tie. Almost no difference in performance between the two.

Klaviyo's help center says text-only emails "often see higher click rates than fully designed HTML emails." Maybe on some lists. But "rules" like that flip from list to list. Within one category in my data, 4 brands, emoji in subject lines helped two brands and hurt the other two. I'd expect format to behave the same way.

So I don't pick a format to squeeze out performance. I pick it based on two things: how fast I need the email live, and how much I need to show.

Why I default to plain text

When performance is about even, the practical stuff decides it.

• It goes live fast. No design queue, no image exports, no layout testing. You can write it in the morning and send it after lunch.
• It's quick and to the point. Nobody scrolls past a hero banner to find out what the email is about.
• The CTA is impossible to miss. With nothing else on the page, one highly visible button or link gets all the attention.
• It guides attention well. One idea, one ask, one place to click.

The trade-off: it's hard to stack links in a plain-text email without it looking spammy. So keep it to one ask.

Klaviyo also notes text-only emails are "often most impactful when signed by a member of your team," and that they can be easier for screen readers and smart watches to read. Both are nice bonuses.

When I pick a designed email

When the email has to show a lot of product. For a consumable brand, that usually means:

• Bundles and big sales. People need to see what's in the box and what it costs.
• Gift guides and multi-product roundups. Lots of products to show at once. I'd still keep one main destination, like a collection page.
• Lots of flavors, sizes or colors. Words alone make people work too hard.
• A multi-item abandoned cart. Showing every item they left is easier with images.

A single-product launch or restock can go either way. A haircare brand's launch email made $31,059 from 395 orders, and a launch like that can work as plain text with one big CTA or as a designed email built around the product. More on launches in product launch emails.

When I do design, my SOP comes from a teardown of 50 top emails: 600px wide, one CTA destination and a trust bar (a strip that makes buying feel safe, like reviews or shipping). Even when an email shows a lot of product, that rule holds: one main destination.

Plain text vs designed: a side-by-side

How I write plain-text emails

There's no big formula here. My approach is simple:

• Quick and to the point. Say what's happening in the first line or two.
• One highly visible CTA. Put it on its own line or use a simple button so nobody misses it.
• Don't stack links. One destination. A second one starts to look spammy.
• Short paragraphs. One to three sentences.

Subject lines come from the same place as everything else I write: a brand's past winners, not a blank page. A few patterns from my subject line bank fit plain text especially well: proof or testimonial ("2 weeks later, she said this:") and objection or question ("Before you make a decision:"). Short, specific, lightly curious and not overly polished. More on the copy itself in ecommerce email copywriting.

How do you decide for your own list?

Start with the brief. Every campaign on my calendars gets a brief before anyone writes copy, and one line of it is the email direction: plain text or designed, and why. If the email is one idea and one product, it's usually plain text. If it needs to show a lot of product, it's designed.

Then test it on your own list:

1. Pick one flow email or one campaign type. A post-purchase email is a good start.
2. Build both versions with the same offer and the same link.
3. Split the audience and send both.
4. Judge by click rate and revenue per person. Not opens. Across 4 consumable brands I pooled data from, click rate tracked revenue at 0.65 and open rate at 0.32.

If the results come out about even, like mine have, pick the one that's faster for your team to ship.

Where these numbers come from

The emoji and click-versus-open findings come from 4 consumable brands and 2,897 campaigns. It's a small sample, so treat them as directional. The launch number comes from one haircare brand I've worked with, described by category instead of name. The text-only email details come from Klaviyo's help center.

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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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