Internet Explorer 11 "won't slow with 100 tabs open"

Unveiling the new browser alongside Windows 8.1 at the company's Build conference in San Francisco, Microsoft executives claimed IE11 delivers the fastest performance of any Windows browser.

"The browser is no longer a commodity - the browser is a way to differentiate the operating system," said Dean Hachamovitch, corporate vice president of Internet Explorer.

"If you compare the limited experience, with other browsers on other devices, with what you can do with IE11... it looks like the web is the killer app," he added.

Hachamovitch claimed the browser delivers a number of performance improvements over its predecessor. Tab handling has been improved, so that tabs which haven't been opened for some time don't consume system memory or CPU resources. "You can have 100 tabs open without costing you battery, or memory or performance," said Hachamovitch, backing up his claims with a demonstration showing minimal impact in the Windows Task Manager.

IE11 also pre-fetches and even pre-renders sites that are linked to from the current tab - such as a list of search results, for example - improving the user experience by delivering top search results almost instantaneously when the user clicks on them. That same pre-rendering technology is used on web articles with multiple pages, with the browser pre-loading the second page, which the reader can access with a single swipe of the finger.

Touch improvements
Microsoft has also improved touch support. The handling of hover menus that pop out further options when the mouse if hovered over them has been enhanced for touchscreen users. IE11 is also the first browser to offer touch support for HTML5's drag-and-drop command, which is increasingly used for uploading photos to websites.

Building on the Pinned Sites concept first introduced with Windows 7, IE11 allows website owners to take advantage of the new larger tile size offered in Windows 8.1, by offering live previews of their sites if users pin them to the Start screen.

Other minor improvements include the option to select thumbnails for favourite websites, and customised software keyboard layouts for web forms - the @ sign and .com buttons will appear when entering text into the "email address" field on shopping sites, for example.

Microsoft has also been borrowing ideas from other browsers. IE11 users can now access tabs open on other devices, and a new Reading List app allows users to save web articles for later browsing.

IE11 will ship with Windows 8.1, and Hachamovitch ignored the "no comment" prompt from Microsoft's PR handlers to suggest that it will also appear on Windows 7 too.