Preview your email in 108 combinations of the most popular email clients and mobile devices.

Unlike web browsers, email clients are far more strict when it comes to HTML and CSS standards. Just because your email renders properly in a web browser does not mean it will render correctly in every inbox. Our email testing service allows you to preview your email in 7 operating systems, 6 web browsers, and 40 email clients - all within one click.


Does your email look beautiful everywhere?

Preview your campaigns across 30+ email clients and devices and get screenshots in minutes.

See how your message looks in the preview pane, and with images on and off.

Works with your existing email software

Litmus doesn’t send your emails; we’re not another email provider. Litmus is a simple, web-based application
that is the perfect complement to VerticalResponse, MailChimp, or any other mailing tool you’re using.
Litmus is the email marketer’s secret weapon for bulletproof campaigns.


Use Inbox Inspection to make sure your email design looks great in all the major email clients and mobile apps. There are approximately a trillion different clients out there, so we do the work for you by automatically selecting your readers’ 10 most‑used clients.

Design aside, Inbox Inspection also helps you stay out of trouble by looking for words and phrases that trigger spam filters, then telling you specifically what’s spammy about your email. Trust us—it’s better to find out ahead of time if your message looks like spam.


In email marketing, what you see is not what your readers see. Literally.

The lovely HTML email template you or your designer sent to your email account may look great to you. But once that email lands in the inboxes of your list, it can look very different.

How can that be?

Lack of email standards

First, there are no established standards for rendering (“displaying”) email.

This means that webmail services (like Windows Live Hotmail) and email clients (like Thunderbird) each have their own unique way of interpreting the HTML that makes up your email.

Common sense suggests that they’re all going to do a pretty similar job of it. Unfortunately, that isn’t always the case…particularly as your email’s design gets more sophisticated and makes more use of CSS.

An uncooperative email client can distort your carefully crafted copy and optimized layouts, hurting response rates in the process.

Consider something as simple as the “p” tag used to define paragraphs in HTML text. Gmail separates the paragraphs nicely:


Email preview tools

These three issues mean you need to see how your email displays in all the important webmail and email client interfaces out there so you can identify, research and correct any problems.

You could set up your own test accounts at webmail services, install various email clients on local PCs and invest in different mobile devices, then send test emails to build up a “picture” of how you stand in terms of cross-client display compatibility. All of which is, frankly, impractical.

Fortunately, there are several low-cost tools that will do this preview work for you. You upload or send a copy of your email and they show you screenshots of how that email looks in various display environments.

If you use an ESP (email service provider), check to see if such a tool is built into their service. If not, there are various standalone tools that offer this functionality.