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High Performance

Super Speed

With faster start-up times, rapid graphics rendering and improved page load speed, Firefox 4 is full of major performance improvements you’ll notice instantly. From integrating Compartments and more efficiently managing JavaScript objects to supporting ECMAScript5 and building the brand new J?gerMonkey JavaScript engine, we’ve been working hard under the hood to make this the most powerful Firefox ever.

Crash Protection

Firefox provides uninterrupted browsing when there is a crash in the Adobe Flash, Apple QuickTime or Microsoft Silverlight plugins. If one of these commonly-used plugins crashes or freezes, it won't affect the rest of Firefox. Instead, you can simply reload the page to restart the plugin and try again. Learn more about plugins.

Real World Performance

Having a super fast JavaScript engine is definitely important, but since those changes are often measured in milliseconds sometimes what matters even more is the way the browser feels when you’re actually using it. That’s why we’re constantly optimizing Firefox to be great for the way you use the web – things like making new tabs open up more quickly, or having the Awesome Bar provide results even faster. In the end, it’s about getting you where you need to go as quickly and easily as possible.

3D on the Web

WebGL brings 3D graphics to Firefox, opening the door for developers to create vivid games and new kinds of visualizations and experiences for the Web.

Hardware Acceleration

Experience super-fast graphics acceleration of video and Web content with a new layers-based graphics system that takes advantage of Direct2D and Direct3D on Windows and OpenGL on Mac.

Advanced Security

Instant Web Site ID

Want to be extra sure about a site’s legitimacy before you make a purchase? Click on its favicon for an instant identity overview. Another click digs deeper: how many times have you visited? Are your passwords saved? Check up on suspicious sites, avoid Web forgeries and make sure a site is what it claims to be.

Instant Web Site ID screenshot

Content Security Policy

The Content Security Policy in Firefox is designed to shut down cross-site scripting attacks by providing a mechanism for sites to explicitly tell the browser which content is legitimate. The browser can then disregard any content that has not been blessed by the site, keeping you protected in the process.

Customized Security Settings

Control the level of scrutiny you’d like Firefox to give a site. You can even enter exceptions—sites that don’t need the third degree. Customize settings for passwords, cookies, loading images, and installing add-ons for a fully empowered Web experience.

Parental Controls

Enforce parental control settings you’ve entered on Windows 7 to stop unwanted downloads and more.

Secure Updates

Firefox looks for a secure connection before installing or updating add-ons, third-party software, and Personas.

Private Browsing

Sometimes it’s nice to go undercover: turn this feature on and protect your browsing history. You can slip in and out of private browsing mode quickly, so it’s easy to go back to what you were doing before as if nothing ever happened. This feature is great if you’re doing your online banking on a shared computer or checking email from an Internet café.

Private Browsing screenshot

Anti-Virus Integration

Firefox integrates elegantly with your Windows anti-virus software. When you download a file, your computer’s anti-virus program automatically checks it to protect you against viruses and other malware, which could otherwise attack your computer.

Anti-Phishing

Shop and do business safely on the Internet. Firefox gets a fresh update of forgery sites a whopping 48 times a day, so if you try to visit a fraudulent site that’s pretending to be someone you trust (like your bank), a warning message will stop you before any harm is done.

Clear Recent History

Clear all your private data or just your activity over the past few hours with a few quick clicks. You have full control over what to delete, and then your info is gone for good—on your own computer or the one at your local library. It’s that easy.

Anti-Malware

Firefox protects you from viruses, worms, trojan horses, and spyware delivered over the Web. If you accidentally access an attack site, it will warn you away from the site and tell you why it isn’t safe to use.

Do Not Track

Many sites track your online behavior and sell that data to advertisers. If that makes you uncomfortable, Firefox lets you tell sites you want to opt out of behavioral tracking and keep your browsing habits private.

Forget This Site

Having second thoughts about having visited a certain site? Remove every trace of ever having been there!

Securing Website Connections

Firefox keeps attackers from intercepting your sensitive data by automatically establishing secure connections to websites that offer secure https servers.

Automated Updates

Firefox will automatically let you know when there’s a new version available, so you can make sure your browser is always up-to-date with the latest and greatest security fixes.

Outdated Plugin Detection

Plugins are small bits of third-party software built by companies like Adobe Systems or Apple to power videos, animation and games. They can be major security risks when they get out of date, so we’ve built an easy tool to help you stay current. Check your plugins.