# Edge’s Internet Explorer mode is supported through at least 2029: inventory the legacy sites that still need it > Microsoft says the Internet Explorer 11 desktop application ended support on certain operating systems on June 15, 2022, and that IE mode in Microsoft Edge will be supported through at least 2029, with at least one year’s notice before it ends. Only sites configured by policy, such as through the Enterprise Mode Site List, open in IE mode. - Canonical URL: https://update.dsesecurity.com/updates/edge-ie-mode-supported-through-2029-enterprise-site-list-legacy-apps/ - Publisher: Detection Systems & Engineering (DSE Security) - Author: DSE Security Editorial Team - Published: 2026-10-19T00:27:39+00:00 - Modified: 2026-10-19T01:55:06+00:00 - Last reviewed by DSE: 2026-10-19 - Resource type: Guide - DSE priority: Advisory - Topics: Cybersecurity, IT - Reading time: 2 minutes ## What you need to know Microsoft says the Internet Explorer 11 desktop application ended support on certain operating systems on June 15, 2022, and that IE mode in Microsoft Edge will be supported through at least 2029, with at least one year’s notice before it ends. Only sites configured by policy, such as through the Enterprise Mode Site List, open in IE mode. ## Potentially affected Organizations with legacy web applications, such as older access control, video, timekeeping or line-of-business portals, that still need Internet Explorer behavior. ## DSE recommendation DSE recommends keeping an owned Enterprise Mode Site List that names every site still needing IE mode, with a retirement plan for each before Microsoft’s notice arrives. ## Article Microsoft says the Internet Explorer 11 desktop application ended support on certain operating systems on June 15, 2022, and that IE mode in Microsoft Edge will be supported through at least 2029, with at least one year’s notice before it ends. Only sites configured by policy, such as through the Enterprise Mode Site List, open in IE mode. ## Source facts Microsoft’s [Internet Explorer and Microsoft Edge lifecycle FAQ](https://learn.microsoft.com/en-us/lifecycle/faq/internet-explorer-microsoft-edge) says the IE11 desktop application ended support for certain operating systems on June 15, 2022, that Internet Explorer 11 is the last major version, and that the retired desktop application has been permanently disabled on certain versions of Windows 10. It says Microsoft is committed to supporting IE mode in Microsoft Edge through at least 2029 on supported operating systems, and will give a minimum of one year’s notice before IE mode’s end of support. Microsoft’s [IE mode overview](https://learn.microsoft.com/en-us/deployedge/edge-ie-mode) says IE mode uses the Trident MSHTML engine from IE11 for legacy sites and the Chromium engine for modern ones, and that only sites configured by policy use IE mode, either through the Enterprise Mode Site List or the policy that sends all intranet sites to Internet Explorer. IE mode supports document modes, ActiveX controls and browser helper objects but not Internet Explorer toolbars, and it requires current Windows and Edge updates and Internet Explorer 11 enabled in Windows Features. ## Applicability Use this for Windows fleets that still run sites needing Internet Explorer behavior. IE mode is supported only on supported operating systems, so operating system end-of-support dates still apply. ## DSE recommendation DSE recommends keeping an owned Enterprise Mode Site List that names every site still needing IE mode, with a retirement plan for each before Microsoft’s notice arrives. Avoid sending all intranet sites to IE mode, ask each vendor for a modern-browser version of its portal, and treat ActiveX-dependent tools as replacement candidates. ## Verification Review the site list quarterly, remove entries for sites that now work in Edge’s default mode, and confirm each remaining entry has an owner and a target retirement date. ## Official references [Microsoft Lifecycle FAQ — Internet Explorer and Microsoft Edge](https://learn.microsoft.com/en-us/lifecycle/faq/internet-explorer-microsoft-edge). [Microsoft Learn — What is Internet Explorer (IE) mode?](https://learn.microsoft.com/en-us/deployedge/edge-ie-mode). Reviewed October 19, 2026. ## Primary reference - Name: Microsoft Lifecycle FAQ — Internet Explorer and Microsoft Edge - Authority: Microsoft Learn - URL: https://learn.microsoft.com/en-us/lifecycle/faq/internet-explorer-microsoft-edge - Source publication date: Not stated by the source ## Citation and use Preferred citation: “Edge’s Internet Explorer mode is supported through at least 2029: inventory the legacy sites that still need it,” DSE Security, https://update.dsesecurity.com/updates/edge-ie-mode-supported-through-2029-enterprise-site-list-legacy-apps/ Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/ Usage and citation policy: https://update.dsesecurity.com/usage/ Copyright © 2026 Detection Systems & Engineering. All rights reserved.