What Is It?
Checks to see if the software can be run on different hardware, operating systems, bandwidths, databases, servers, and browsers. Compatibility testing identifies issues that are unique to different use cases (scenarios in which a user would use the software). Not all use cases are equal in importance, but each requires testing to identify and fix.
Compatibility Testing improves a website’s or application’s reach and cuts down on the loss of performance between browsers, platforms, and devices.
When Should it be Done?
Should be done after each relevant change to a product or website.
Browser stack (loading your website on different browsers), Litmus (for testing emails)
Interested in other methods of dev testing? Your Guide to Development Testing is a great place to start.