Email HTML Preview
HTMLPreview HTML emails in simulated Gmail, Outlook, and Apple Mail frames. Check for compatibility issues.
Why HTML email testing is essential
HTML emails render differently across email clients because each client has its own CSS engine and restrictions. Gmail strips external stylesheets and many CSS properties, Outlook for Windows uses the Word rendering engine (which does not support modern CSS), and Apple Mail supports most CSS but has its own quirks. Sending an untested email can result in broken layouts, missing images, and unreadable content for a significant portion of your audience.
Common email HTML pitfalls
The most frequent email HTML issues are: using display: flex or grid (not supported in Outlook), relying on external stylesheets (stripped by Gmail), using CSS animations (ignored by all email clients), and setting background images (not rendered in Outlook). The safest approach is table-based layouts with inline CSS styles. This tool validates your HTML against known email client limitations and warns you about unsupported properties before you send.
Best practices for email HTML
Use tables for layout instead of divs with flexbox or grid. Inline all CSS styles directly on elements. Set explicit widths on table cells. Use web-safe fonts with fallbacks. Keep total email width under 600px for optimal display across devices. Test with a dark mode preview since many email clients now default to dark mode. Include alt text on all images since many clients block images by default.
Frequently Asked Questions
Can this tool send test emails?
No. This tool previews your email HTML locally in your browser. It simulates the visual frame of different email clients but does not send actual emails. For live testing, use services like Litmus or Email on Acid.
Why does my email look different in Outlook?
Outlook for Windows uses the Microsoft Word rendering engine, which does not support modern CSS properties like border-radius, flexbox, grid, background images, or box-shadow. Use table-based layouts with inline styles for Outlook compatibility.
What CSS properties are safe to use in HTML emails?
Safe properties include: color, font-family, font-size, font-weight, text-align, background-color, padding, margin, border, width, height, and table-related properties. Avoid: flexbox, grid, position, float, animations, transitions, box-shadow, and external stylesheets.
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