Orbit web apps
Orbit web apps
Check your email HTML file size, Gmail clipping risk, and common issues.
Gmail truncates any HTML email larger than 102KB and replaces the cut-off portion with a 'View entire message' link that very few recipients click. Your CTAs, unsubscribe link, and legal footer all risk landing below the fold. Here's why the limit exists and how to stay under it.
The 102KB cap applies to the raw HTML source, not the rendered page.Source · GoogleGmail sender guidelinesOfficial Google documentation covering email size, clipping behavior, and sender requirements.support.google.com/a/answer/81126 That means everything counts: HTML tags, inline CSS, <style> blocks, hidden preheader text, tracking pixels, ESP-injected wrappers, and HTML comments. Images themselves don't count — they're referenced by URL — but inline data-URI images do count, and they destroy your budget fast.
Once the message is handed off to the recipient's ESP for rendering, any content past 102KB is replaced with a '[Message clipped] View entire message' link. Everything after that point is hidden from the default view. The click rate on that link is in the low single digits.
A typical ESP adds 8–20KB of wrapper markup on top of whatever you built: link-tracking redirects, personalization tokens expanded to their full values, an unsubscribe footer, and DKIM metadata. If your raw template is at 85KB, your delivered email can easily cross 102KB — and the preview in your ESP won't show that wrapper expansion.
Always check the final rendered size against a real send or a production-fidelity preview, not the draft editor's file size. The Email Size Checker above accepts the post-wrapper HTML directly so you see the number that actually reaches Gmail.
1) Inline data-URI images. A single 30KB logo encoded as base64 will eat a third of your budget. Always host images externally and reference them by URL. 2) Unused CSS. Template builders generate hundreds of class definitions you never use. Strip them. 3) HTML comments. Build-tool banners, conditional comments for Outlook, developer notes — they all ship. Run a comment stripper before production. 4) Duplicate inline styles. Every <td> with the same style block repeats every byte. Consider a <style> block scoped with Outlook-safe selectors. 5) Overly precise pixel values. 'margin-top: 12.7389px' costs bytes you don't need. 6) Embedded fonts. Skip @font-face; use web-safe fallbacks and save the weight.
Under 60KB is a comfortable headroom for most templates. Over 80KB starts to feel precarious. Over 100KB you're gambling. The checker above flags warnings at 80% and errors at the clip threshold so you can catch the problem before you send.
Built into Orbit
Orbit's email production skill generates Braze-ready HTML, validates it against the Gmail 102KB limit automatically, flags inline data URIs before you send, and produces cross-client previews in Gmail, Outlook, and Apple Mail in one step.
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Free email HTML size checker that flags the most common production issues: Gmail clipping risk (102KB limit), inline data-URI images, bloated CSS, missing alt text, and excessive HTML comments. Paste your HTML, get a report in seconds.
Email developers, lifecycle marketers, CRM managers, and QA teams shipping production email.
Using Claude?
Inside Orbit for Claude, every email Claude produces is size-checked, alt-tagged, and CSS-optimized automatically. The Email Production skill keeps templates under the Gmail 102KB limit, strips bloat, and flags accessibility issues, all before the template ever reaches Braze. Free for everyone — the Claude extension is the power-user upgrade, not a gated feature.