What is Litmus?
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You've built an email, you think it looks great, and then a subscriber replies to say it's broken in Outlook. That's exactly the problem Litmus was built to solve.
Litmus is an email testing and analytics platform. Its core feature is rendering previews across 90+ email clients and devices, so you can see how your email actually looks in Gmail, Apple Mail, Outlook, dark mode, mobile, and more, before you hit send. Rendering tools like Litmus do this by running your HTML through real or emulated email clients and returning screenshots.
Beyond previews, Litmus also checks your links, runs spam filter tests, flags accessibility issues, and gives you post-send engagement analytics like read time and email client share. That last part is genuinely useful for understanding your actual audience.
Where Litmus shines is team collaboration. Designers, developers, and marketers can all review the same email in one place, leave comments, and sign off before sending. If you're a solo sender or a small team doing occasional campaigns, that workflow probably isn't worth the price tag. Litmus pricing starts at several hundred dollars a month, and that's the honest thing to say upfront.
For larger teams, agencies, or brands sending frequently to large audiences, the cost-per-send math works out quickly. Catching one broken email before it goes to 200,000 people pays for a lot of months.
If you want to compare it to a similar tool, Email on Acid covers similar ground and is worth a look side by side.
Not sure if you need a full testing platform or something lighter? Our SOS hotline is free, and we're happy to help you figure out what actually fits your setup.
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