Email Preview Tool FAQ

General

What is an email preview tool?: It helps you see how your HTML email will look in different email clients and devices before you send it. This eliminates guesswork and reduces the risk of sending broken emails.
Is MailViewr free to use?: Yes! MailViewr is completely free. You can preview your HTML emails across multiple clients without any cost or signup required.
Do I need to create an account?: No account is required. Simply paste your HTML and start previewing immediately.

Why does my email look fine in my builder but broken in Outlook?: Email clients don't share the same HTML/CSS support. Outlook desktop uses Microsoft Word's rendering engine, which ignores many modern CSS properties like flexbox, grid, and certain padding/margin rules.
Which email clients does MailViewr support?: MailViewr supports previews for Gmail (web, Android, iOS), Outlook (desktop, web, mobile), Apple Mail, Yahoo Mail, and other popular clients.
Why do colors look different in dark mode?: Some email clients automatically invert or adjust colors in dark mode to improve readability. This can affect backgrounds, text, and images. Always test dark mode previews to ensure your design remains readable.
Why aren't my web fonts showing?: Most email clients don't support web fonts. Gmail, Outlook, and Yahoo will fall back to system fonts. Always specify fallback font stacks like 'Arial, Helvetica, sans-serif'.

Do I really need previews if my ESP already shows mobile/desktop views?: Those previews often represent devices, not real client rendering quirks. Client-specific previews reveal where Gmail vs Outlook behaves differently, catching issues ESP previews miss.
What should I test first?: Start with a high-impact combo: Gmail (mobile) and Outlook (desktop). If it works there, you'll catch most common breakages early. Then expand to Apple Mail and other clients.
Should I use tables or divs for email layouts?: Tables are still the most reliable choice for email layouts. While modern clients support divs, Outlook desktop requires table-based layouts for consistent rendering.
How do I make my emails responsive?: Use fluid tables with percentage widths, media queries where supported, and mobile-first design. Test thoroughly since media query support varies by client.

Can I preview emails with external images?: Yes, MailViewr will load and display external images in your preview. Make sure your image URLs are accessible and use HTTPS for best compatibility.
Is my email HTML stored or shared?: No. Your HTML is processed locally in your browser and is not stored on our servers. Your email content remains private.
What CSS properties should I avoid?: Avoid flexbox, grid, position: absolute/fixed, advanced selectors, and CSS variables. Stick to inline styles, basic padding/margin, and table-based layouts for maximum compatibility.

Try MailViewr free and see how your HTML emails render across clients.