Litmus Test
01 Definition
Litmus Test meaning: Previewing an email across many clients and devices using the Litmus platform.
A Litmus test uses the Litmus platform to render an email across dozens of mail clients, devices, and browsers so senders can spot display problems before sending. It shows how the message looks in Outlook, Gmail, Apple Mail, and more. It is a proprietary tool, and results reflect the clients Litmus supports.
Also called
Why it matters
How Litmus Test fits the work
Emails render differently everywhere, so seeing real previews before sending helps you catch broken layouts that would otherwise reach subscribers.
In context
Before launch, a marketer runs a Litmus test and finds the header breaks in older Outlook, then fixes the code and retests.
Practical note
Litmus is one vendor among several such as Email on Acid; its previews cover many but not every client version, so unusual setups may still differ.