Limitations of HTML Email

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The majority of email clients don’t support every type of HTML content you see on the web. Web browsers are able to display scripts, animations, and complex navigation menus, while your typical email inbox isn’t built to handle this type of content.

In this article, you’ll learn about content types to avoid in your email designs, and what to use instead.

Email HTML v. Web HTML

The viewing technology of a typical email client isn’t as up-to-date as a web browser. Web browsers display interactive, dynamic content, and they update often. But interactive elements like Flash, JavaScript, or HTML forms won’t work in most email inboxes.

View the table below to learn more.

Safe to use

Use with caution

Do not use

  • static, table-based layouts

  • HTML tables and nested tables

  • template width of 600px-800px

  • simple, inline CSS

  • web-safe fonts

  • background images

  • custom fonts

  • wide layouts

  • image maps

  • embedded CSS

  • JavaScript

  • <iframe>

  • Flash

  • embedded audio

  • embedded video

  • forms

  • <div> layering


Safe to use: widely supported by most email clients

Use with caution: limited support from most email clients

Do not use: not supported by most email clients

Elements to Avoid

MailChimp's predesigned templates do not include elements that are known to fail in email inboxes. If you insert these elements with Code content blocks, our system will remove them to make sure your subscribers can view your campaigns successfully.

Use with Caution

Background Images

Background images won’t display in every email client. Popular clients like Outlook and Hotmail automatically remove background images from your campaigns. If your background image is removed, your text content may not be visible at all if it’s lightly colored. Instead, insert a smaller image in your campaign.

Review our Design For Email guide for design ideas that are compatible with popular email clients.

Custom Fonts

MailChimp’s Drag and Drop Editor provides web-safe fonts only. Most email clients don’t support CSS properties like @font-face, @import, and that import custom fonts into web pages. For consistent display, use web-safe fonts.

Or use images to display custom-font headlines, and include the body content as text. Without this balance of text and images, spam filters can flag your campaign.

Wide Templates

Your subscribers often open campaigns on mobile devices or in the preview pane of desktop email clients. Email viewing panes are narrow, so they’ll cut off your message if it’s wider than 600-800px.

Read our layout guide for tips and strategies for building narrower templates.

Do Not Use

The elements below are blocked by nearly all major email clients. Support is either extremely limited, or nonexistent.


JavaScript is a programming language that makes web content interactive. It’s common in websites, but the vast majority of email clients block scripts since they can hide malicious content. Avoid all JavaScript.

Try gifs to make your content more engaging.

Iframe Elements

An <iframe> (inline frame) is an HTML element that embeds content from one website into another. Inline frames are often used to insert advertisements, video, audio, or forms in other websites. Iframes often contain scripts, so most email clients block them.

Instead, link to the content you want to display in your campaign.


Flash displays animations and graphics on websites, but most email clients block it.

Instead, try gifs to make your content more engaging.

HTML Forms

Text fields, text inputs, radio buttons, and checkboxes are simple HTML form elements, but the submit button often requires Javascript. Some email clients will display forms, but unfortunately, subscribers won’t be able to submit them. Avoid HTML forms, and consider an alternative.

Instead, try a simple poll or a MailChimp survey integration to gather responses from subscribers, or insert a link to a web form.

Embedded media

Autoplay and click-to-play media won’t play in an inbox unless your subscriber’s email client supports HTML5 <video> and <audio> tags. Only one major email client, Apple Mail, supports these tags, so it’s best to avoid embedded media and consider an alternative.

Instead, share a video player link with MailChimp’s merge tags or video content blocks. To send audio files, share an audio file link.

Email HTML Design Resources for Coders

Whether you’re new to email HTML or you’ve coded plenty of emails before, these resources can help you design templates that look great in a variety of email clients.

Email Design Reference

Provides resources on design, development methods, code samples, and downloadable email blueprints to help you design and build emails.

Collection on Code-Your-Own Templates

Provides step-by-step articles on custom-coded template topics.

Email Design Guide

Provides campaign style, design, and layout tips in article form.

Designer’s Resource Guide: Design Your Campaign

Provides a summary of the HTML design practices that work best in MailChimp.

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