First look at Firefox 4

Firefox 4 offers features like tab management, remote device sync, and speed improvements.

Firefox 4 has finally arrived, after months of delays and after rival Web browsers Internet Explorer 9 and Chrome 10 already shipped. The browser gets a speed boost and several feature enhancements that are so significant that they all have their own proper names, like Panorama, JaegerMonkey and Firefox Sync. Were they worth the wait? Let's take a look.

Related slideshows:

First look at Chrome 10

First look at Microsoft Internet Explorer 9

Tabs moved

The first, obvious difference is that the tabs are in a new location, up at the top. Plus, if you start typing a site name in one tab, Firefox checks to see if you already have that site open in another tab – and then lets you switch to that tab instead of opening a new instance. If you don't like the tabs on top, you can switch back by going to View > Toolbars > Tabs on top.

Tab management

Speaking of tabs, are you one of those people who open so many tabs you can't keep track of them all? Firefox 4 has a feature called "Panorama" that lets you organize tabs into groups. You can then easily zoom into any tab in any group. To activate the feature, choose "Customize" on your toolbar and add the "Tab Groups" button.

App tabs

If you keep a certain site open all the time, you can right click on the tab and choose "Pin as App Tab," which will create a mini-tab that loads every time you start Firefox. Mozilla suggests things like Web mail, but you can do this with any kind of Web site. The example here shows Slashdot, Gmail and Twitter.

Firefox Sync

Web browsing gets cloud-ified with Firefox Sync. Integrated into Firefox 4, the service lets you put your browsing history, bookmarks, tabs and passwords into the cloud, which means you can have all of that information with you when you go to another computer or a mobile device running Firefox. It sounds like a useful service, but obviously, privacy and security are key issues here. Mozilla says it uses encryption end-to-end.

Add-ons manager

Going to Tools > Add-ons get you to an attractively arranged interface for showing you not only what extensions and plug-ins you already have installed, but also what add-ons you might be interested in.

Speeded up

Firefox has added a JavaScript engine called JaegerMonkey that is supposed to speed things up. I ran this benchmark (your mileage may vary) on Firefox 3.6 and then again on Firefox 4, and the rating improved from 118 to 272. But to compare Firefox 4 against the latest browsers from Microsoft and Google, my colleague Julie Bort ran the Peacekeeper benchmark (pictured) and found that Firefox still trails them substantially. Her full results are here .

HTML5 support

Firefox 4 improved its HTML5 support quite a bit with the new release. Using this benchmark , the browser went from 159 in Version 3.6 to 264 in Version 4. My colleague Jon Brodkin recently sized up IE9 , which scored 135, and Google Chrome, which scored 301.

Want more?

Note that more technical details of the changes in Firefox 4 are available here and performance measurements are here .

Related slideshows:

First look at Chrome 10

First look at Microsoft Internet Explorer 9