Sakai 12 is designed to work with modern browsers. Recommended browsers (those with the most QA testing effort against them) are Google Chrome, Safari, and Mozilla Firefox. Microsoft Edge and IE 11 should work fine. If you are upgrading from an earlier version of Sakai (pre-Sakai 11), please make sure that you don't have the property X-UA-Compatible:IE set, or it may make Microsoft IE 11 behave as though it is an earlier browser version and therefore not work. Sakai should work on most modern tablet and mobile devices.