Microsoft has just launched Internet Explorer 11 Release Preview for Windows 7, so it’s no surprise that the company has already started a media campaign to promote the browser.

In a blog post describing the improvements it made in Internet Explorer 11, Microsoft claims that its new browser is 30 percent faster than any other browser on Windows 7, while also loading pages 9 percent quicker than Internet Explorer 10.

If you’re curious to find out what’s behind this significant speed boost, Microsoft has a pretty good explanation: it all comes down to improvements made to Chakra, its internal JavaScript engine. Here’s what the company says about it:

“Internet Explorer 11 advances the performance leadership of our JavaScript engine, Chakra, while ensuring compatibility, interoperability, and security. As we improve performance for real-world sites, IE11’s JavaScript performance on benchmarks like WebKit SunSpider continues to lead compared with latest version of other browsers.”

But that’s not the only improvement available in IE11, the company noted. The browser also packs better compatibility with existing web sites and support for new standards, offering a similar experience and performance no matter if you are using a mouse, a keyboard, a pen or touch.

“IE11 Release Preview for Windows 7 adds new user controls for the Standard Delivery Profile for Closed Captioning. With the new control, accessible from the Internet Options menu, users can customize how captions appear in the browser, even overriding the default styling provided by the video source. This customization further advances IE11 as the best browser for professional-quality online video without plugins,” the tech giant explained.

In addition to all these improvements, IE11 also packs improvements to the in-browser F12 developer tools, including an enhanced console, a debugger, DOM explorer, better memory management, and networking tweaks.

As you know, Internet Explorer 11 is the default Windows 8.1 browser and is available in two different flavors in the modern OS, giving users the option to launch it in either desktop or Metro environments.