Summary
While most modern email clients support HTML rendering, making it the dominant format, the percentage of emails viewed as HTML vs. plain text varies. B2C leans heavily toward HTML, while B2B, particularly in security-conscious sectors, sees a higher (though still minority) proportion of plain text views, possibly up to 10%. The specific industry or domain matters. Most clients display HTML by default, however, tracking engagement with plain text emails is difficult. Always provide a plain-text version, especially since spam filters are less likely to flag them, mobile users make up more than half of all email opens and you can alienate people by only sending HTML emails.
Key findings
- HTML Dominance with Nuances: Most modern email clients support and display HTML emails. However, there is not a magic number for how many people use plain text.
- Audience and Security Matter: B2C audiences primarily view HTML. B2B, especially in security-focused industries, have more plain text views.
- Tracking Challenges: Tracking opens and clicks in plain text emails is difficult.
- Mobile Optimization is Key: A large percentage of email opens occur on mobile devices. Optimize for this
- Spam isn't the issue: HTML emails are not an issue with spam filters these days.
Key considerations
- Always Include Plain Text: Always include a plain-text version as an alternative, for user choice, spam filter avoidance, and accessibility.
- Domain-Specific Considerations: For security-conscious domains, consider plain text to ensure deliverability and user experience.
- HTML Coding Standards: Adhere to HTML coding standards to ensure proper rendering across clients.
- Mobile Optimization is Key: Optimize HTML emails for mobile viewing.
- Test Extensively: Test rendering and deliverability across multiple platforms and clients.
What email marketers say
11 marketer opinions
The percentage of emails viewed in HTML versus plain text varies significantly depending on the audience and industry. While HTML emails are generally preferred for their design capabilities and branding opportunities, a significant portion of B2B recipients, particularly in high-security environments, may view plain text emails. It's important to note that tracking opens and clicks in plain text emails is challenging. Additionally, while most modern email clients support HTML, optimizing for mobile is crucial, and providing a plain text alternative ensures accessibility for users who prefer it or have security concerns.
Key opinions
- Audience Matters: B2C audiences primarily view HTML emails, while B2B audiences, especially in high-security industries, have a higher prevalence of plain text views (up to 10% or more).
- HTML Dominance: The majority of email clients support HTML rendering, indicating that most users will see the HTML version of an email if it's well-formatted.
- Limited Plain Text Tracking: Tracking opens and clicks is difficult in plain text emails, making it harder to gauge engagement.
- Mobile Usage: A significant portion of email opens occur on mobile devices, highlighting the importance of optimizing HTML emails for mobile viewing.
- Spam Filters: Inclusion of HTML is no longer an indicator of spam. Good sender reputation and following guidelines is more important.
Key considerations
- Audience Preference: Consider your target audience's preferences and security requirements when deciding between HTML and plain text. Sending both is preferable.
- Mobile Optimization: Ensure HTML emails are optimized for mobile viewing to provide a positive user experience for the majority of recipients.
- Accessibility: Provide a plain text version to cater to users who prefer it or have email clients that don't fully support HTML rendering.
- Deliverability: Maintain a good sender reputation and follow email marketing best practices to ensure high deliverability rates for both HTML and plain text emails.
- Alternative text: Text only in your emails can still be useful.
Marketer view
Email marketer from Sendinblue.com explains that plain text emails are easier to read on mobile devices and may get through spam filters better.
24 Nov 2021 - Sendinblue.com
Marketer view
Email marketer from SuperOffice.com states that the general user experience with HTML emails is overwhelmingly positive. But it also states that a poor user experience with HTML is down to poor formatting, large images and cluttered designs. These all contribute to a poor user experience.
5 Sep 2023 - SuperOffice.com
What the experts say
6 expert opinions
Modern email clients overwhelmingly support and display HTML emails by default. While statistically, nearly all clients *can* render HTML, some older systems, specialized domains (like .mil), or security-conscious industries may necessitate or benefit from plain text alternatives. Although the majority will see HTML, having a plain text version as a fallback remains good practice.
Key opinions
- HTML Support Universal: Almost all modern email clients support and display HTML by default.
- Limited User Control: End-users typically cannot force their email client to display the plain text version if an HTML version is available.
- Legacy & Secure Environments: Specific industries or domains, particularly government and security-focused sectors, might still require or prefer plain text.
- Text Only Users Exist: There is still a group of users on text only.
Key considerations
- Plain Text Fallback: Always include a plain text alternative, even if most users will see the HTML version.
- Domain-Specific Requirements: Consider plain text only for certain sensitive domains. Do research.
- Client Display: Even with HTML support, ensure emails render correctly across various clients.
- Security Considerations: Organizations can take HTML capabilities away and this should be a consideration
Expert view
Expert from Email Geeks explains that statistically, there are no email clients that don't support HTML, and any normal mail client will display the HTML version. There are a few rare special cases where the text/plain version will be used (crappy, old ticketing systems, obsolete smartwatches).
18 Mar 2022 - Email Geeks
Expert view
Expert from Spam Resource explains that most modern email clients are capable of rendering HTML emails, so the vast majority of users will see the HTML version.
22 Sep 2022 - Spam Resource
What the documentation says
5 technical articles
Most popular email clients (Apple Mail, Gmail, Outlook) support HTML rendering. Plain-text emails are less likely to be flagged as spam. Outlook displays HTML by default if capable. MIME defines email content types, with HTML offering richer styles. Non-standard HTML coding can lead to rendering issues across different platforms.
Key findings
- Popular Clients Support HTML: Leading email clients like Apple Mail, Gmail, and Outlook support HTML email rendering.
- Plain Text = Less Spam: Plain-text emails are less likely to be flagged as spam filters.
- Outlook Prefers HTML: Outlook prioritizes displaying HTML emails when the client supports it.
- HTML Offers Rich Styles: HTML enables richer styling and formatting compared to plain text.
- Coding Standards Matter: Non-standard HTML can cause rendering problems due to differences in platform interpretation.
Key considerations
- Optimize for HTML: Design for HTML, as it's widely supported and offers better styling options.
- Include Plain Text Alternative: Provide a plain text version to avoid spam filters and accommodate clients without HTML support, but be aware tracking might not be possible.
- Standard HTML Coding: Adhere to HTML coding standards to ensure consistent rendering across platforms.
- Testing is Essential: Test emails on various platforms to catch rendering issues.
- Testing Deliverability: Test deliverability of both plain text and HTML emails.
Technical article
Documentation from EmailToolTester explains how to test email deliverability rates. They state that Plain-text email is far less likely to be flagged as spam as it is often perceived as more safe.
21 Jul 2024 - EmailToolTester.com
Technical article
Documentation from Microsoft.com states that Outlook will display HTML emails by default if the email client is capable of rendering HTML.
1 Jul 2021 - Microsoft.com
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