Email Size Checker

Gmail stops rendering an email once the message body passes roughly 102 KB. Everything after that point is replaced with a "Message clipped" link, and most people never click it. In practice that means your call to action, your footer, your tracking pixel, and your unsubscribe link can all vanish from the version your subscribers actually read. Paste your HTML above to see the real size of your email, how close it is to the clipping threshold, and what is taking up the space.

Why Gmail clips emails at 102 KB

The 102 KB limit is a rendering decision, not a delivery limit. Gmail still delivers the whole message; it simply refuses to display more than the first 102 KB inline and offers to open the rest in a new window. The threshold applies to the message body after encoding, which is why an email that looks like 90 KB in your editor can still be clipped once quoted-printable or base64 encoding inflates it. Clipping also hides your list-unsubscribe footer from readers, which pushes people toward the spam button instead, so it is a deliverability problem and not only a design problem.

What actually counts toward the limit

Only the HTML counts, not your images. A 900 KB hero image hosted on a CDN adds nothing to the message size, because the email contains a URL rather than the file. What does count is inline CSS on every table cell, nested table layouts, tracking parameters repeated on dozens of links, base64-encoded images embedded directly in the markup, invisible preheader padding, comments left in by your builder, and any large blocks of duplicated markup. Base64 embedding is the single fastest way to blow past 102 KB, since encoding inflates a file by about a third. Our text-to-image ratio checker and attachment size checker cover the other two weight problems.

How to shrink an email that is too big

Work in this order. Remove base64-embedded images and host them instead. Run the HTML through our CSS inliner so styles are applied once rather than repeated per element, then delete any style rules that no longer match anything. Flatten nested tables: three levels of nesting for a single button is common and costly. Cut repeated tracking parameters down to the minimum that your analytics actually reads. Strip editor comments and whitespace. Shorten the email itself, because a 1,500-word newsletter genuinely is heavier than a 400-word one. Aim to land under 60 KB, which leaves headroom for the personalization and link rewriting your platform adds at send time.

Size limits in other email clients

Gmail is the strictest of the major web clients, and it is also the one most of your list uses, so 102 KB is the number to design against. Yahoo Mail and Outlook.com render considerably larger messages without truncating, though both get slower. Apple Mail has no practical clipping threshold. Mobile clients are constrained more by download time on a poor connection than by any hard byte limit. Because Gmail sets the effective ceiling for everyone, the safe rule is a single one: stay well under 102 KB and you are fine everywhere. If you would rather not think about this per campaign, the Sequenzy email editor keeps HTML lean, compresses images automatically, and warns you before a campaign crosses the clipping threshold.