Right now Edge extensions are still a bit experimental. You’ll need to join the Windows Insider Program, sign up for the fast ring, and install Windows 10 Build 14291 to get them. But once you do that, you can try out some of the first extensions that change the behavior of Microsoft’s new web browser.
Right now you need to first download an extension and then sideload it. Eventually Microsoft will let you install extensions from the Windows Store.
Preview extensions include Microsoft Translater, which automatically translates web pages from 50 different languages (something which Google Chrome can do without an extension, by the way), Mouse Gestures, and a version of Reddit Enhancement Suite.
Microsoft says additional extensions including Adblock, LastPass, and Evernote are on the way.
Other updates in Windows 10 Build 14291 include support for pinned tabs in the Edge browser, a “paste and go” option to quickly enter text from your clipboard into the location bar to navigate to a web page or conduct a web search (with “paste and search”), and updated Maps and Alarms & Clock apps.