Email preview
& render tester
Paste your email HTML, preview it live at desktop and mobile widths, and run a compatibility linter that catches the markup and CSS that Gmail, Outlook and Apple Mail are known to strip or break — before you hit send.
Heads up: this is a readiness linter and a local preview, not a real render. It scans your HTML for the patterns known to break in each client and shows it in a sandboxed browser frame — it does not open your message in actual Gmail, Outlook or Apple Mail. Treat it as a fast pre-flight, not a substitute for a real inbox test.
Paste some email HTML above to run the compatibility linter.
Every inbox is a different browser.
Email clients render with wildly different engines — what looks perfect in one can fall apart in the next.
Outlook runs on Word
Outlook on Windows renders HTML with Microsoft Word's engine. Flexbox, grid, float, background images and modern CSS are ignored — table-based layouts are the only reliable option.
Gmail strips CSS
Gmail removes external stylesheets, restricts <style> in some contexts, and clips messages over ~102 KB. Inline styles and lean markup keep your email intact.
Apple Mail is the friendly one
Apple Mail and iOS use WebKit and support the most modern CSS. It is the easiest target — but building only for it guarantees breakage elsewhere.
Images off by default
Many clients block images until the reader opts in. Alt text, solid background colors and a bulletproof structure keep the message readable without a single image loading.
Design once, render everywhere.
Bitelio's editor outputs bulletproof, tested HTML — table-based layouts, inline styles and Outlook-safe structure by default, so you spend less time fighting inboxes. Free to start, no credit card required.