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The Truth About HTML vs Text Emails: Real Data From 1000+ Campaigns

IInfotanksDeveloper

April 30, 2025

New research brings clarity to the HTML vs text emails debate. Our analysis of over 1000 campaigns shows plain text emails captured 60% of conversions from existing customers and 49% from non-customers. The data about plain text vs HTML email performance revealed unexpected patterns. Plain text emails had higher open rates, while HTML emails connected better with new prospects. These results challenge what we know about email format effectiveness. Adding even a simple GIF to a plain text message reduced opens by 37%.

Our team studied metrics in various industries to determine which format best serves specific goals. This piece examines how text vs HTML email performance changes based on your audience and what you want to achieve. Companies that want to build a data-backed email strategy can use our IInfotanks Email campaign service to put these findings into practice.

Main Point 1

The differences between HTML and plain text emails are crucial for marketing strategies. HTML emails are enhanced versions that include formatting, styles, links, and multimedia, functioning like mini web pages in your inbox. They use HyperText Markup Language for a rich visual experience. In contrast, plain text emails consist only of unformatted text, making them compatible with all email clients and devices, appearing exactly as typed.

Historically, all emails were plain text, utilizing ASCII (American Standard Code for Information Interchange), which was standardized in 1986. ASCII includes basic characters but lacks details about font, size, or color.

Key Differences Between HTML and Plain Text Emails:

Visual Appearance: HTML emails can add images, videos, custom fonts, colors, and interactive elements like buttons. Plain text emails show only text with no styling options.

Creation Complexity: HTML emails need more time and effort to design because of their complex structure and visual elements. Plain text emails are easy to write and focus on content rather than presentation.

Deliverability: Plain text emails rarely trigger spam filters because they have no hidden code that spammers could use. Email security systems check HTML emails more carefully.

Rendering Consistency: Email clients don’t show HTML content the same way, which can change how your email looks to recipients. Plain text emails look the same everywhere.

Loading Speed: Plain text emails load right away due to their simplicity. HTML emails take longer to load because they have a complex structure and rich content.

Tracking Capabilities: HTML emails allow detailed tracking and analytics, including open rates through embedded HTML snippets. Plain text emails have limited tracking options.

Accessibility: Plain text emails work better for users with visual impairments who use screen readers. HTML emails can be harder for these users unless properly optimized.

HTML emails faced significant issues in the early 2000s due to a lack of compatibility with many email clients and services like Gmail, which limited HTML features. Smartphones further complicated matters until responsive design became standard in the mid-2010s.Both HTML and plain text emails play crucial roles in digital marketing, and your choice should reflect your brand identity, message type, and audience expectations rather than just following trends.

Today, modern HTML emails have addressed many previous limitations, but understanding when to use each format is essential for effective email marketing. Infotanks’s Email campaign service assists businesses in selecting the right format based on their goals and audience needs.

Main Point 2

Email format shapes how recipients connect with your message – it’s not just about looks. Our research comparing html and text emails proves that format matters just as much as content.

Professionalism and Brand Identity
Your email’s format mirrors your credibility and professionalism. A steady, well-laid-out format builds your brand’s image in all communications. This helps set your company apart while deepening your brand’s identity. Many marketers choose between html or plain text formats based on their brand’s position.

Engagement and Response Rates
The choice matters a lot – your email’s format drives engagement. Studies reveal that students who read formatted messages found advertised jobs more appealing and remembered facts better. The right format can boost your conversion rate when comparing plain text and html emails:
- HTML emails let you track open rates with embedded snippets, giving you insights that plain text can’t
- Visual content grabs reader’s attention quicker than plain text, making information stick

Readability and Information Processing
People spend only 15-20 seconds reading an email. Clear fonts, smart spacing, descriptive headings, and well-placed bullet points make your content easy to read. On top of that, readers like documents without extra fluff that might overshadow key points.

Mobile Responsiveness
Marketing emails lead to purchases for 60% of consumers. But emails that look bad on mobile devices push people to unsubscribe. A responsive design works well no matter where people read it.

Legal and Technical Considerations
Your format choice affects email delivery. HTML vs plain text decisions determine if your message lands in inboxes or spam folders. HTML-heavy emails often end up in promotions tabs instead of primary inboxes.

The Conversion Impact
Format drives results. Research shows that well-designed emails spark interest and drive sales. Welcome emails bring in 320% more revenue than promotional ones.

IInfotanks’ Email campaign service helps you make smart format decisions. We study your audience’s habits and campaign goals to pick between html and plain text emails. Our data-backed method strikes the perfect balance between looks and deliverability, maximizing opens and conversions.

Your perfect email format depends on your industry, audience’s needs, and campaign goals. Understanding these details will improve your marketing results.

Main Point 3

Email marketing success depends on deliverability. Many marketers don’t fully grasp this vital metric when choosing between HTML and text emails. My analysis of thousands of campaigns shows that deliverability means more than just message receipt – it’s about where your email ends up in the recipient’s inbox structure.

Your message needs to land in subscribers’ inboxes primary, social, or promotional and avoid the spam folder. This is what we call email deliverability. Inbox placement tracks what happens next by determining which folder gets your email. This difference matters a lot since emails in the primary inbox get much more attention than those in promotional tabs or spam folders.

Our data shows clear deliverability patterns when comparing plain text and HTML emails:

Plain text emails get better deliverability rates than HTML versions
Spam filters scrutinize HTML emails more due to their code complexity and formatting
A single broken HTML tag could send your message to spam

HTML emails can be effective if coded correctly and accompanied by a plain-text version, as missing either can raise red flags with email providers. The use of images is crucial; too many or poorly optimized visuals can trigger spam filters, and larger emails are scrutinized more closely. Plain text emails generally perform better because they are safer, compatible with all email clients, and resemble personal communication, which email providers favor.

However, abandoning HTML isn’t necessary. Our tests indicate that a mix of both formats often yields the best results. Infotanks’ Email campaign service helps businesses overcome deliverability challenges by implementing proper authentication protocols and creating responsive designs that maintain good text-to-image ratios.

Beyond format, factors such as sender reputation, engagement history, and technical setup play significant roles in email deliverability. Ultimately, whether to use plain text or HTML depends on your audience and campaign goals—transactional messages benefit from plain text, while brand-building efforts can successfully utilize HTML.

Main Point 4

Email open rates tell quite a story in the battle between HTML and text emails. Many marketers think flashy design elements help get emails opened, but the opposite is true.

HubSpot looked at over half a billion marketing emails and found something surprising: plain text emails consistently achieve higher open rates than their HTML counterparts. The research showed that more HTML elements led to fewer opens.

The numbers tell the story clearly:

Adding a GIF to a plain text email drops opens by 37%
A single image reduces opens by 25%
Heavy email templates see 23% fewer opens compared to hybrid approaches

This pattern stayed consistent in all test scenarios. World Concern’s open rates jumped 35% when they switched from HTML-rich emails to plain text.

The better performance of plain text isn’t about deliverability – both formats delivered similarly. Email services now filter promotional-looking messages away from main inboxes. One researcher put it well: “Just because something says it’s been delivered doesn’t mean it’s actually in a noticeable place of someone’s inbox”.

Recent data shows average email open rates are around 42.35%, much higher than before.

The rates vary by industry:

Retail and e-commerce: 35.90%
Education: 37.35%
Finance: 26.48%
Manufacturing: 32.03%

Overall averages indicate that plain text emails lead when formats are compared. HTML emails require tracking pixels for open measurement, but plain text emails can’t track opens, only clicks. Since email clients block images by default, HTML open rates are often underreported. This explains why marketers, like Litmus, prefer plain text strategies, as tests show they yield better open rates from both customers and non-customers. At IInfotanks, we help companies choose effective email formats based on data. Our findings suggest simpler formats gain more visibility in inboxes.

The connection between email format and open rates is influenced by how email providers operate, pushing marketing emails down and prioritizing personal ones. Thus, even well-designed HTML emails may struggle to capture attention.

Main Point 5

The most surprising insights from our HTML vs text emails analysis come from click performance. Our study of over half a billion marketing emails shows that plain text emails get by a lot more clicks than visually rich HTML versions.

Most marketers believe beautiful HTML emails should convert better because images explain offers better. The evidence tells a different story. HTML emails get fewer opens and clicks after people open them.

Multiple A/B tests revealed a clear pattern:

Plain text emails lost 2.3% clicks after adding a GIF
Image-based HTML templates reduced clicks by 21%
Simple HTML templates got 5.3% more clicks than complex designs

Plain text emails significantly outperform GIF and image-heavy HTML emails, receiving 42% and 51% more clicks, respectively. HubSpot’s research highlights that email feels like a 1-to-1 interaction, making plain text more effective in driving actions.

For example, Litmus found that existing customers converted at a rate of 60% with plain text emails, while non-customers achieved 49%. In every industry, plain text emails also show 21% higher click-to-open rates and 17% higher click-through rates than HTML emails.

Many companies are now adopting hybrid approaches, using A/B testing to optimize formats. Marketers should focus on different click metrics: click-through rate (CTR) measures clicks per delivered email, while clickthrough rates assess clicks relative to opens, with plain text winning in both. The preference for simplicity is backed by psychology; HTML emails tend to feel less personal, leading to hesitation. Studies indicate that straightforward communication elicits stronger responses. Consequently, simplifying email design, even within HTML formats, can enhance effectiveness.

Main Point 6

The real test of email effectiveness goes beyond open and click rates – it’s all about conversion results. The battle between html vs text emails shows some surprising patterns that turn common marketing beliefs upside down.

How format affects conversion rates

Real campaign data tells us which format works best. A breakthrough study by Litmus showed that plain text style emails generated 60% of conversions from existing customers. This turns the tables on what we thought about HTML’s power to persuade. Plain text emails did well with non-customers too, bringing in 49% of conversions.

Simple emails work better than you might think. HubSpot ran tests to see if HTML elements helped performance. They found that “opens drop 37% for a hybrid with a GIF vs plain text email”. This big drop hurts conversion chances before people even read the content.

Your audience type makes a big difference in how email formats work. The research shows clear patterns:

Plain text works better for existing customers
New customers show mixed format priorities
Mobile users are 65% more likely to convert

Personal touch drives email success. Plain text emails feel like one-on-one communication, appealing to loyal customers. A researcher noted, “It’s like someone’s talking directly to you.” After the email click, the landing page must match the email’s promise. A clean, consistent design keeps visitors focused on taking action. Effective email design can enhance conversion rates; studies show CTA buttons outperform text links by 28%, and personalized calls-to-action perform 202% better than generic ones.

Mobile matters more than ever, with 46% of emails opened on mobile devices. A responsive design is crucial to prevent unsubscribes.

At IInfotanks, our email campaign service customizes formats based on data, testing plain text versus HTML for different audiences. The right email format depends on your target audience and goals, with no one-size-fits-all answer. Understanding these patterns leads to better email marketing results.