Mozilla has released Firefox 4 for Windows, Mac, and Linux. This is a significant release for the browser, bringing a cleaner interface, a major speed boost, stronger privacy controls, and a long list of improvements for both everyday users and web developers. Here is a full look at what is new.
Performance
Mozilla is billing Firefox 4 as the fastest version of the browser ever released, claiming up to six times the performance of the previous version. Start-up times, page load speeds, and web app performance have all been improved, with hardware accelerated graphics added to better handle the rich and interactive websites that are becoming the norm.
On the developer side, the JavaScript engine has been updated with the new JägerMonkey JIT compiler alongside enhancements to the existing TraceMonkey JIT and SpiderMonkey interpreter. The result is faster page loading and better performance for web apps and games.
A Cleaner, Smarter Interface
Firefox 4 introduces a streamlined interface with several new tab management features. App Tabs let you pin frequently visited sites like webmail, Twitter, or Flickr so they always have a home in your browser. Switch to Tab detects when a site is already open and takes you there instead of loading a duplicate. Panorama lets you drag and drop tabs into groups, making it much easier to manage a heavy tab workload without losing your place.
Privacy and Security
Firefox 4 puts privacy front and centre. The browser now leads the push for a universal Do Not Track standard, giving users a straightforward way to opt out of behavioural advertising tracking. HTTP Strict Transport Security (HSTS) automatically forces secure connections where available, protecting against man-in-the-middle attacks during login. Content Security Policy (CSP) adds another layer of protection by allowing websites to tell the browser exactly which content is legitimate, helping to prevent cross-site scripting attacks.
Mozilla has also fixed flaws in certain web standards that previously allowed third parties to access your browsing history without permission.
Sync and Customisation
Firefox Sync lets you access your browsing history, bookmarks, open tabs, passwords, and form data across multiple computers and mobile devices. It is a feature that has become essential as more people move between devices throughout the day. The new Add-ons Manager makes it easier than ever to discover and install from over 200,000 add-ons, giving you full control over how the browser looks and behaves.
HTML5 and Developer Tools
Firefox 4 extends its HTML5 support significantly, covering hardware accelerated high-definition video via WebM, 3D graphics, offline data storage, professional typography, touchscreen interfaces, and the Mozilla Audio API. CSS, Canvas, and SVG support have all been improved to give developers more to work with when building modern web experiences.
One particularly welcome addition is plugin crash protection. If Adobe Flash, Apple QuickTime, or Microsoft Silverlight crashes or freezes, it no longer takes the rest of the browser down with it. Simply reload the page to restart the plugin and carry on.
Download Firefox 4
- Available free from mozilla.com for Windows, Mac, and Linux