Microsoft Edge (codenamed Spartan) is a web browser developed by Microsoft, released on 29 July 2015 as the default browser for Windows 10, replacing Internet Explorer. It is designed to be a lightweight web browser with a layout engine built around web standards. It does not support ActiveX, Browser Helper Objects or any other form of plug-in besides Adobe Flash Player. However, it adds new features such as integration with Cortana, annotation tools, and a reading mode. Extension support was added to Edge with the release of the Windows 10 Anniversary Update on 2 August 2016.
Microsoft Edge will be the default browser on both the PC and mobile device editions of Windows 10, replacing Internet Explorer 11 and Internet Explorer Mobile.
Microsoft Edge uses a new "Edge" layout engine forked from Trident that is "designed for interoperability with the modern web". The new "Edge" engine will be used by default across Windows 10, and pages can be rendered in the legacy MSHTML engine for backwards compatibility with enterprise-specific websites and software.
Internet Explorer 11 will remain available alongside Microsoft Edge on Windows 10 for compatibility purposes; it will remain nearly identical to the Windows 8.1 version and not use the Microsoft Edge engine as was previously announced.
Microsoft Edge will integrate with Microsoft's online platforms: it integrates with the Cortana digital assistant to provide voice control, search functionality, and dynamic, personalized information related to searches within the address bar. Users can make annotations to web pages that can be stored to and shared with OneDrive. It also integrates with the Reading List unction to sync content between devices, and provides a Reading Mode that strips unnecessary formatting from pages to improve their legibility.
In an August 2015 review by Dan Grabham of Techradar of Windows 10, Microsoft Edge was praised for its performance, albeit not being in a feature-complete state at launch.
Andrew Cunningham of Ars Technica praised the browser for being "tremendously promising", and "a much better browser than Internet Explorer ever was", but criticized it for its lack of functionality on-launch.
Thom Holwerda of OSNews criticized Edge in August 2015 for its hidden URL bar, lack of user friendliness, poor design and a tab system that is "so utterly broken it should never have shipped in a final release". He described the browser's implemented features, "Infuriating doesn't even begin to describe it" and "some sort of cosmic joke".
Data from August 2015, a few weeks after release, showed that user uptake of Edge was low, with only 2% of overall computer users using the new browser. Among Windows 10 users usage peaked at 20% and then dropped to 14% through August 2015, as users tried it and many stopped using it in favor of other browsers.