Plain Text vs. HTML what is the Best Email Format

In 2016, I wrote a blog post called Plain Jane Email Marketing. Now, as we move into 2025, I’ve updated it to show why plain-text emails still matter. Which format should you use for your email campaigns—plain text or HTML?  I submit the following:  

Email technology has existed for over half a century. Early on, plain text email evolved into plain text email marketing, which was widely accepted at the time. Then, in the 1990s, one of our customers discovered how to send HTML emails using our system. While Chris wasn’t the only reason email changed so dramatically (😊), web-based email was becoming globally accessible—making HTML email possible for everyone.

This was a dream for email marketers.  They quickly discovered the power of color, design, and images, along with the ability to track clicks and opens in an HTML environment. But a few decades later, we’re seeing a renewed shift back to plain-text emails.  

The Rise (and Plateau) of HTML Emails:  

When HTML first came onto the scene, it changed everything. Email became visually engaging and measurable:  

• HTML Templates: Pre-designed, drag-and-drop templates made it easy to create appealing messages without coding knowledge.
• Responsive Design: As mobile usage soared, templates evolved to be mobile-friendly.
• Tracking and Analytics: HTML emails provided robust metrics: open rates and click-throughs—making it easier to measure ROI.

Today, almost every Email Service Provider (ESP) offers built-in HTML templates or compatibility with templates found online. We provide one free fully custom template with our service, or you can hire a designer to create a fully customized look.

However, now it seems that customized email templates are being outperformed by plain-text emails.  in key metrics such as deliverability and open rates.  How could that be?  

Higher Deliverability rates for plain text can be contributed to:  

• Complex HTML, which can trigger filters or be stripped away by certain email clients – especially in security-conscious industries.
• Because plain text is universally recognized and rarely blocked, those type of messages stand a better chance of landing in the Primary Inbox rather than Promotions or Spam.
• A Simple, text-based email can look more like a direct message from a friend.  Recipients respond to authenticity, and a “from” name they trust can dramatically improve open rates.
• When you keep images and design elements to a minimum, it can also help your emails stand out.
• Regardless of the smartphone, e.g. Android Phone, iPhone, smartwatch, or older device, plain text displays quickly and cleanly with minimal scrolling. And there’s less bandwidth usage too.
• Some devices automatically block images in HTML emails, forcing the user to take extra steps to view them.
• Smartwatches and other emerging wearable tech often display only a text version. With more people adopting these devices, you don’t want half your email unreadable on a watch.

But HTML does have its Advantages as it offers:

• Eye-Catching Design: Showcasing product images, brand logos, or vibrant designs.
• Detailed Metrics: Marketers love the in-depth data on opens, clicks, and conversions.
• Immediate Visual Appeal: If you’re selling a highly visual product (like fashion or home décor), HTML can help you stand out—when done well.

However, HTML has a Darkside:  

• Risk of Improper Rendering: Coding issues or differences in email clients can break your design, leaving an unprofessional look.
• Potential for Lower Engagement: Many subscribers tire of overly commercial messages, especially if images are slow to load.
• Increased Spam Filter Sensitivity: HTML-heavy designs often raise the suspicion in spam filters.

Which Format Is “Best”? Test, Test, Test  

The only way to know what works for your audience is to run A/B tests:  

• Plain Text vs. Minimalist HTML
• Single-Image vs. Multiple-Image HTML
• Short Subject Lines vs. Long Subject Lines

Measure open rates, click-through rates, replies, and overall engagement. You may find that even one simple image can outperform a text-only email—or that your audience strongly prefers the personal feel of plain text.  

Going Forward in 2025  

Even with AI accelerating content creation, subscribers seem to still want genuine human communication. Plain-text emails come across as direct, personal, and trustworthy—three qualities likely to be even more important as automated tools flood the marketplace with generic messages.  

At the same time, HTML designs are far from obsolete. They can enrich brand storytelling, highlight product visuals, and provide deeper analytics—just be sure not to sacrifice readability and authenticity for design flair.