It was at the Build 2019 developer conference where Microsoft first announced IE Mode for their Chromium-based Edge browser. After enabling a flag, you could then use Internet Explorer within a tab in Edge.
Only a few weeks later, the “Show this page using Internet Explorer” option in the menu isn’t there anymore, even if you still have the flag enabled.
That menu entry was always intended only for internal debugging purposes, and we've removed it now that IE mode is formally released. IE mode is a enterprise-only feature. Only the admin controls whether a site ends up in IE mode or not (this is key to the security model).
— Sean Lyndersay (@SeanOnTwt) July 24, 2019
Unfortunately, only IT admins will be able to open websites in IE mode from now on, as per the security model. Reportedly, the reason for the feature disappearing is because IE Mode is meant to be an enterprise feature. The option to manually launch a site in an IE tab was meant for “debugging purposes”.
Here’s how the Microsoft blog explains the function of the Internet Explorer Mode in Edge:
One of the features available for evaluation is Internet Explorer mode, a feature that integrates IE11 natively into Microsoft Edge. Internet Explorer mode allows users to navigate seamlessly from a modern web application to one that requires legacy HTML or plugins. You’ll no longer need a “two-browser” solution.
We know that most of our customers are using IE11 in their environments. One thing that our customers made clear to us is that their web apps that rely on IE11 tend to be critical to many of their business processes. The apps work well and don’t change, which allows customers to focus their IT resources on other problem areas. Any solution we provide would need to just work with their sites.
The team designed Internet Explorer mode to meet that need, with a goal of 100% compatibility with sites that work today in IE11, including full support for IE’s doc modes, as well as ActiveX controls, like Silverlight and Browser Helper Objects (BHOs). In addition, Internet Explorer mode appears visually like it’s just a part of the next Microsoft Edge, providing users with the latest UI features, like a smarter address bar and new tab page, and greater privacy controls for the modern web.
By leveraging the Enterprise mode site list that many customers have already built and deployed to support the two-browser solution, IT professionals can enable users of the next Microsoft Edge to simply navigate to IE11-dependent sites and they will just work. Navigating back to a modern site will be seamless. No need for a separate window or tab.
From now on, unless you’re an IT admin, the function isn’t for you. You can still use Internet Explorer the old fashioned way if you really miss it.