The plain text vs html email debate gets treated like a religious argument online, and it shouldn't be, because the honest answer is that both have real strengths and the right choice depends on what you're sending and to whom. Here's an even look at both sides.
Plain text email is exactly what it sounds like, unformatted text with no images, no colored buttons, no custom fonts, just words the way you'd type them in a basic text editor. HTML email is built with actual markup, letting you control layout, add images, use brand colors, and design buttons that look like buttons instead of underlined blue text.
Most people assume HTML is the more "professional" or "modern" choice by default, and plenty of successful senders use it well, but plain text has genuine advantages that get overlooked because it looks less impressive in a screenshot.
Plain text tends to read as more personal, since it looks like something a person wrote rather than something a marketing team designed, and that perception can drive higher trust and reply rates, especially for cold outreach or one-to-one style newsletters. HTML gives you tools plain text can't touch, branded visuals, clear calls to action with buttons that stand out, and layout that can guide the eye through a longer email, which matters more for ecommerce or content-heavy sends.
Neither format is inherently better at getting opened, since open rate is driven mostly by sender reputation and subject line, not body format. Where they genuinely differ is in what happens after the open, and in a few deliverability details worth knowing.
Heavily designed HTML emails, especially ones with a poor text-to-image ratio, can read as more promotional to spam filtering systems, which is part of why so much HTML marketing email lands in Gmail's Promotions tab rather than Primary. Plain text emails, or HTML emails built to look plain text, tend to land in Primary more often, because they resemble the kind of email a person sends another person rather than a bulk campaign.
That said, HTML itself isn't the problem, poorly coded HTML is. Broken markup, excessive image weight, sketchy links, and spammy formatting patterns are what actually trigger filters, not the presence of HTML formatting itself. A clean, well-coded HTML email with a healthy amount of real text can perform just as well as plain text.
Plain text tends to win for cold outreach, founder-to-audience newsletters, one-to-one style updates, and any email where the goal is a reply or a feeling of direct communication rather than a click on a designed button. It also renders identically everywhere, since there's no layout to break across different mail clients or screen sizes, which removes a whole category of testing you'd otherwise need to do.
HTML wins for ecommerce, product launches, anything with multiple items or offers to display, and anywhere brand consistency matters for recognition across a long relationship with a subscriber. A well-designed HTML email can communicate more in less scroll distance than plain text can, since layout and visual hierarchy do work that paragraphs alone can't.
My actual recommendation for most senders is to lean plain text or lightly-styled HTML for relationship-building sends like welcome sequences and regular newsletters, and save fuller HTML design for promotional sends like launches and sales, where the visual polish earns its place. Whichever you choose, mobile rendering matters either way, which I cover in mobile friendly email design, and the deliverability side of this decision connects directly to what a healthy average email open rate actually looks like for your list.
Often, yes, though it's not guaranteed. Plain text and lightly-styled HTML tend to read as less promotional to filtering systems, which can help with Primary tab placement, but sender reputation still matters more than format alone.
Not in true plain text, no, since that's part of the definition. Many senders use a middle ground: HTML that's styled to look like plain text, with minimal formatting and maybe one small logo, which keeps some of the deliverability benefit while allowing basic branding.
No. It's still the standard for ecommerce, product marketing, and any brand that relies on visual consistency. The shift is more that senders are getting smarter about when to use it rather than defaulting to it for every single email.
It depends on the goal. HTML with a clear button often gets more clicks to a specific link, while plain text often gets more replies. If your goal is a click, HTML usually helps. If your goal is a conversation, plain text usually helps.
Whichever format you choose, it only works if it reaches Primary. If you're curious whether your current HTML template is hurting your placement, I offer a free <a href="/audit">deliverability audit</a> to check.