HTML Email Size Checker

Gmail clipping is when Gmail truncates your email and replaces the cut-off portion with a "[Message clipped] View entire message" link. This happens when the HTML source of your email exceeds a certain size threshold. Clipping is a significant deliverability concern because most recipients never click that link, meaning your call-to-action, unsubscribe link, or tracking pixel at the bottom of the email may never load. Clipped emails also tend to have lower engagement rates, which can hurt your sender reputation over time.

Gmail clips emails when the HTML source code exceeds approximately 102 kilobytes (102,400 bytes). This is the raw HTML size, not the rendered visual size, and it includes all inline CSS, HTML tags, tracking pixels, and any embedded content. It does not include the size of externally hosted images -- those are loaded separately by the email client. The 102KB limit applies to the message body only, not headers or attachments. We recommend keeping your emails under 80KB to maintain a comfortable safety margin, since email service providers sometimes add their own tracking code and wrapper HTML during sending.

The most effective strategies for reducing HTML email size are: (1) Remove unused CSS -- many email builders include large CSS blocks where only a fraction of styles are actually used. (2) Minify your HTML by removing unnecessary whitespace, comments, and line breaks. (3) Simplify your layout -- deeply nested table structures add significant markup weight. (4) Use shorthand CSS properties (e.g., "margin: 10px 20px" instead of setting each side individually). (5) Replace large inline images with externally hosted images using img tags. (6) Remove hidden or conditional content blocks that are not visible to most recipients. (7) Shorten tracking URLs and reduce the number of unique links. Most email builders like Litmus and Email on Acid offer HTML minification as a built-in feature.

No, externally hosted images do not count toward the 102KB Gmail clipping limit. Gmail loads images separately from the HTML source, so a 500KB hero image referenced via an img tag contributes only the bytes of the img tag itself (typically 50-200 bytes depending on the URL length and attributes). However, if you embed images directly in the HTML using base64 data URIs, those absolutely count toward the size limit and can dramatically inflate your email size. For this reason, always host images externally and reference them with standard img src URLs. The same principle applies to other externally referenced resources like web fonts loaded via link or import rules.

You can check your email size by pasting the raw HTML source code into our checker above. To get the HTML source: in most email service providers, look for a "View HTML" or "Export HTML" option in the email editor. In Mailchimp, use the Code view. In Klaviyo, use the HTML editor. In HubSpot, export the email template HTML. If you are coding emails by hand, simply paste your complete HTML document. Our tool calculates the exact byte size of your HTML, flags potential Gmail clipping issues, and provides a breakdown of elements that contribute to the overall size. Run this check after your email is finalized but before scheduling the send.