When designing and coding HTML emails, one of the biggest challenges marketers face is email clipping—where a mailbox provider truncates an email, requiring the recipient to click “View entire message” or “Read more” to see the full content.
Understanding these clipping limits can help optimize your email designs, ensuring that key messaging isn’t hidden from your audience. In this post, we’ll explore the HTML size limits across major mailbox providers, particularly focusing on Gmail and iOS Mail, two of the most widely used email clients.
Why Does Email Clipping Happen?
Email clipping typically occurs when the HTML file size exceeds a certain threshold. This includes the HTML, inline CSS, and any embedded elements, but not externally hosted images. When an email surpasses a provider’s limit, only a portion of the content is displayed, and the rest is hidden behind a “View entire message” link.
1. Gmail’s Clipping Limit: 102 KB
Gmail has one of the most well-known and strict clipping limits. If your email exceeds 102 KB, Gmail will truncate the email and append a link saying:
“[Message clipped] View entire message.”
Implications of Gmail Clipping:
- Tracking pixels and analytics issues: If tracking pixels are placed after the 102 KB mark, open tracking may not fire correctly.
- Hidden unsubscribe links: Some compliance-required footer elements may be clipped, leading to deliverability issues.
- Broken design: If inline styles or necessary CSS are clipped, your email may not display correctly.
Tips to Avoid Gmail Clipping:
- Minimize inline styles and redundant HTML tags.
- Use shorthand CSS where possible.
- Remove unnecessary comments and whitespace in the HTML.
- Optimize tables, div structures, and remove unnecessary
<span>elements. - Reduce excessive use of
<style>blocks and prioritize external stylesheets where possible. - Keep email copy concise to minimize HTML bloat.
2. iOS Mail’s Handling of Long Emails
Apple’s iOS Mail app does not have a hard HTML size limit like Gmail but presents a different challenge: it tends to truncate long emails visually, typically when longer than 5,000px.
Unlike Gmail, iOS Mail does not clip based on file size but rather based on scroll length and rendering performance.
Implications of iOS Truncation:
- Content may appear blank: iOS sometimes stops rendering an email when it detects excessive height.
- Longer emails may lead to usability issues: Users may experience difficulty scrolling or may not reach the CTA.
- Rendering inconsistencies: Some CSS-heavy emails may load partially or not at all if they are too long.
How to Optimize for iOS Mail:
- Reduce the number of nested tables and excessive HTML markup.
- Keep content concise and CTA-focused near the top of the email.
- Use progressive disclosure, such as collapsible sections or links leading to a landing page.
- Avoid excessively long one-column emails, as these may trigger iOS’s rendering limit.
Other Major Email Providers’ Clipping Limits
| Email Client | Clipping Limit |
|---|---|
| Gmail | 102 KB (HTML file size) |
| Yahoo Mail | No strict limit, but long emails may render inconsistently |
| Outlook (Desktop & Web) | No specific size limit, but Outlook has rendering quirks that may cause truncation |
| iOS Mail | No hard limit, but long emails longer than 5,000px may not fully display |
| Apple Mail (MacOS) | No known clipping issues |
How to Check If Your Email is Clipped
If you want to test whether your email exceeds clipping limits, try the following:
- Send a test email to a Gmail account and check if “[Message clipped]” appears at the bottom.
- Send test emails to an iPhone using iOS Mail and scroll down to see if all content renders properly.
- Use email preview tools like Litmus, Email on Acid, or the Gmail Developer Console to analyze email size.
Conclusion
Email clipping is a crucial factor in email deliverability and engagement. With Gmail’s strict 102 KB limit and iOS Mail’s unique rendering behavior, it’s essential to keep your email HTML optimized and lightweight. By reducing redundant HTML, optimizing CSS, and keeping messaging concise, you can ensure that recipients see your entire email without interruptions.
